A/C Not Cold Enough For You? [Archive] - MercuryMarauder.net Forums

ShelbyMotorspts

07-26-2006, 03:19 PM

I felt the A/C in my MM was not that great. Did an extensive archive search and found others with the same complaint but then there were others saying how great their a/c worked. Hmmm, is it me or the car?

So I took the car to the dealer this morning and just got a call from them that they need to replace the orifice tube. So in one way I'm happy that they found something wrong and can't wait to get the car back to see how well the a/c works after the repair.

But on the other hand when an orifice tube gets clogged up'd that usually means bigger problems may exist like the compressor self destructing or what the a/c industry calls "black death". Luckily I purchased an extended care warranty that covers the a/c system but if there is enough junk to clog this orifice tube then there is probably more junk coming that will clog the new one.

So has anyone else had the orifice tube replaced?

Steve

BAD MERC

07-26-2006, 03:27 PM

I thought mine sucked too. Even with 40 degree air from the vents my butt and back would sweat through my clothes. The ambient temperature in the car never feels colder than tepid. My windows are all tinted with metallic film and my entire windshield is tinted as well. The L/M dealer said nothing was wrong. Even with my remote start on for 15 minutes- it still takes a 30 minute drive to get tolerable inside. I really don't get it- my 1995 Taurus had air that made my bones hurt. I am really disappointed in the A/C in my Marauder. You would think a 9-year old newer car would have state of the art HVAC. Apparently not.....

Blackened300a

07-26-2006, 03:36 PM

I guess Im lucky because after 10 minutes in a hot and humid day, Im turning the A/C down because Im actually fogging the windows a bit.
I did have my head unit replaced under warranty over the winter. Mayber thats why its freezing in my Marauder

Hotrauder

07-26-2006, 04:51 PM

The FruitPunch has the best AC I have ever had in a vehicle by far. I start the car and before I can get out of the car port it is blowing cold. No surprise, my A. Orifice tube is larger than most. Dennis:beer:

GreekGod

07-26-2006, 05:10 PM

My A/C seems to be better this summer than the last 3 but I'm not at all happy. It does blow 40 to 45 degrees but I must direct the vents on my head to get relief. I'm planning to have them look at it when I bring it in for "uncommanded wiper operation".

I normally drive solo, so I suspect if I had 3 passengers with me on a hot day, the A/C would be inadequate. Hopefully, an A/C expert or a owner with experience with this problem can help us on this forum.

The A/C in the '96 Contour I drove would freeze me out in 10 minutes or less.

For those that don't know, our warrenty deductible is per dealer visit, so get everything fixed or investigated when bringing in for service.

Shora

07-26-2006, 05:21 PM

In order to feel any A/C at all I must close one of the vents on the passenger side. Otherwise, the air (while even in the max setting) is too weak to reach me.

Hotrauder

07-26-2006, 05:28 PM

In order to feel any A/C at all I must close one of the vents on the passenger side. Otherwise, the air (while even in the max setting) is too weak to reach me.

Sounds like you both have blower not AC problems. Check the blower operation. Dennis:beer:

GreekGod

07-26-2006, 05:53 PM

The blower is ok, it's the weak cooling that is the problem.

jimlam56

07-26-2006, 05:53 PM

I recently drove my new Blue MM through some brutal heat on my way home. (CO,KS.MO,TN,LA.MS,AL,FL, 2600 miles)
Outside temps registered by the AC were as high as 112 degrees.
Had the temp set at 74-76 degrees and was comfortable, depending on where the sun was.
Have had a few panthers, never complained about the AC...just don't ask me about power windows...

ShelbyMotorspts

07-26-2006, 05:53 PM

Well I'm hoping for a marked improvment in my a/c. I'll post when I get the car back from the dealer.

My MM is silver with tinted windows. I'm not sure how I would survive with a black MM.

Steve

JMan

07-26-2006, 06:07 PM

I have to reply. This is Panther number five and although it's not an MM, the a/c bites. I know I constantly compare this car with my previous ones, but in this instance, there is no comparison. My wife's Marquis will test your erectile tissue in the summer after being parked in the sun. The differences are her car is white with white leather/ light grey interior. My car is SB with DC interior. The other big difference is the amount of refrigerant my car holds. The newer cars hold much less refrigerant than the older cars. I looked it up - the '03 and up cars only hold 38ozs of refrigerant. I serviced mine last fall and replaced 38ozs. Still only fair cooling. I want freezing. Guess I'll have to play with it a little and see what happens. If there are any revelations, I'll pass it on to the collective!

J

P.S. You guys just think it's hot elsewhere!

Hauser717

07-26-2006, 07:39 PM

my 1995 Taurus had air that made my bones hurt.

I don't remember, did the '95 models still run R-12? If so, there is your answer. R-134a is to R-12 as light beer is to real beer. It gets the job done, but just not as satisfying.

JMan

07-27-2006, 03:44 AM

I don't remember, did the '95 models still run R-12? If so, there is your answer. R-134a is to R-12 as light beer is to real beer. It gets the job done, but just not as satisfying.

By January of '94, all Ford's were equipped with R-134 from the factory.

J

Bluerauder

07-27-2006, 04:15 AM

I felt the A/C in my MM was not that great. ...
So has anyone else had the orifice tube replaced?

Steve
For the past 2 summers, I have felt the same about my A/C. It just didn't seem to be putting out cold air like any other car that I've driven. Even had it in the shop a couple of times and the answer was always the same -- the pressures check out and the coolant ain't leaking.

However, this summer the A/C seems to be working much better and blowing much colder. Maybe my orifice tube finally cleared itself. Don't recall that ever being mentioned by the service department. I am getting awfully close to the 36 month/36,000 mile window -- so I don't like thinking about this "Black Death" syndrome. ;) If and when it goes south .... I'll deal with it then. :rolleyes:

ctrlraven

07-27-2006, 07:19 AM

On a less than 95 degree day the AC feels great anything above that it takes about 10 mins to really get the car feeling cool (not cold). The one thing does bother me is that I can feel the exhaust heat from my knees down and their isnt that much AC blowing down around the feet/leg area.

Ross

07-27-2006, 08:21 AM

I have to think it's your particular AC unit, not a generic problem. I live in Houston where we routinely get both temps and humidity in the 90's, and my AC has worked fine (thank God) for over 3 years.

Merc-O-matic

07-27-2006, 09:23 AM

By January of '94, all Ford's were equipped with R-134 from the factory.

J

That is true!......have a 1994 Town Car with 120K which still
spits "ice cubes".....so cold I have to run the ACC at 78F.

Gotta Love It!:beatnik:

the_pack_rat

07-27-2006, 09:38 AM

For the really humid & sunny days -

I find most cars(not just our MM's) that run 134, work their best using re-circulated(max setting for us) air vs outside air.

Regular a/c is best for low humidity - no sun & night-time conditions.

RoyLPita

07-27-2006, 10:15 AM

I've lost some of my A/C cooling ability wheninstalled my u/d pullies. It still does the job, it just takes a little while longer.

BAD MERC

07-27-2006, 10:21 AM

No, it was indeed R134a.
I don't remember, did the '95 models still run R-12? If so, there is your answer. R-134a is to R-12 as light beer is to real beer. It gets the job done, but just not as satisfying.

ckadiddle

07-27-2006, 12:41 PM

I've lost some of my A/C cooling ability wheninstalled my u/d pullies. It still does the job, it just takes a little while longer.
Oh heck, no underdrives for me then. I love the A/C in my Marauder. We have to back off a bit after about ten minutes at max fan/max cool even in hottest most humid conditions.

Zack

07-27-2006, 12:52 PM

High blood pressure.
A/C is probably fine.

the_pack_rat

07-27-2006, 02:55 PM

I've lost some of my A/C cooling ability wheninstalled my u/d pullies. It still does the job, it just takes a little while longer.
Ya' know so many people swear by them ......

But /\ that /\ very reason above, is why I refuse to even think about going there.

Also ... the extra heat(& more of it year round) in Florida ..... never made me too keen on giving the water pump an easier day of work either(slowing it down). I want all the effort the cooling system will give me & then some.

I test drove & seriously thought about buying a reasonbly priced local Special Edition Mark VII LSC(monochromatic black on black) a couple of years ago .....

And as I was driving it & kind of thinking how the a/c didn't feel like it was doing all that much(ok it SUCKED) ... the owner told me it had under-drive pullies & the originals had been tossed long ago.

Now mind you, it wasn't the U/D pullies that kept me from buying it.

It was a northern car with a re-paint of un-known quality & origin ..... even tho it did look pretty good. I didn't need or want any rust rearing it's ugly head six months after I bought it.

cruzer

07-27-2006, 08:49 PM

Today the outside air temp was 101 degrees-MM was parked at a restaurant for 1 hour--started engine and started timing---30 seconds to colder air---5 minutes to stabilized 70 degrees in med blower and "max a/c" setting. No complaints here.

ShelbyMotorspts

07-28-2006, 02:00 PM

Well got the MM back from the dealer and am not too happy. Almost feels warmer compared to when I took it in. On the ride home I get the following readings:

89 outside temp.

Best it can do on normal a/c is 50.

Switched to max a/c and the best was 46.

Now I know why it felt so bad a few days ago when the outside temp was 100 but 50 degrees on a 89 degree day can't be right.

Service receipt says:

Low side press too high 50 PSI
Replace orifice tube and O rings Evac and recharge pres
Now 175-30 PSI Cools to 44 degrees

The receipt then lists the part #'s for the orifice tube, the O rings and 38 ounces of refrigerant.

So time to do some more research as if my car is normal how can these cars be used as taxi's or PI's with such poor a/c performance.

Bradley G

07-28-2006, 05:10 PM

If it quite working entirely, that would not be :sweat: good!
I keep mine on high. in this 90-100* weather. EATC never catches up to auto setting @75*

ShelbyMotorspts

07-28-2006, 05:33 PM

Smokie

07-28-2006, 06:10 PM

Just so I don't confuse anyone those temp numbers in post #25 are from a a/c thermometer stuck in the dash vent.

Looking thru the archives it seems the pressure numbers of 175-30 from the dealer don't jive with other numbers posted.

Rheinhart (sp?) made a good detailed post a year ago and if I read it correctly with the pressure numbers & temp readings I'm getting it looks like I still have a problem.

Have to decide if I should try another dealer or go back to the same one.

I'l give some info that I hope you find helpful, 50 lbs on the low side is not a for sure an orifice problem, as a matter of fact on a very hot day when idling it can be quite normal.

There are some variables that have to be excluded when you start talking "normal pressures" and "normal outlet vent temperature". First pressure test should be performed with MAX A/C on coldest setting maximum fan speed. Engine should be at about 1500-1800 rpms, not at IDLE.

With an ambient temperature of 85-90 degrees and relative humidity of about 65-75% your pressures should be 190-225 high side, 35-40 low side, vent outlet temp decreases as you decrease fan speed, at high speed at least down to 45 degrees, at low fan speed it can get as low as 38 degrees.

Your low side suction line right at the compressor should be very cold to the touch and sweating profusely, you should see a steady trickle of drops from under your car from the evaporator drain tube.

I hope this helps.

Eric91Z

07-28-2006, 06:30 PM

I have to say (knock on wood), that I am very pleased with the A/C in mine. I am one of those that can start sweating the minute I get out of the shower in the winter. Doesn't take much.

Now, I have 15% window tint on the sides and back and until yesterday did not have a windshield shade for the car. I always parked at work so that the windshield was facing the afternoon/early evening setting sun.

I have actually, for the first time, started using my remote start in the summer, too. I always leave it on AUTO and adjust the temp and fan from the steering wheel. Pretty much never touch it otherwise, unless I am going to VENT or Floor/Defrost.

Anyway, by the time I get my stuff in the car and sit down you can feel it starting to cool. I usually have the AUTO temp set at 60 or 65 when sitting during the day. I will run it at the temp for 5-10 minutes as I go right from work to get on the interstate. 5-10 minutes of interstate driving and I am turning the fan down and the temp to about 68-70. After a good 10 minutes, in this 90+ degree and 90% humidity we have been having, I can turn the temp to about 74-75 for the rest of the trip home and be comfortable. Now and then bump up the fan or drop the temp if the sun is hitting right, but only now and then.

Much better than the Honda Accord I got out of and slightly better than the wife's Ford Five Hundred. I do hope you get it worked out. I would be frustrated, too.

ShelbyMotorspts

07-28-2006, 07:38 PM

Appreciate the input. I do hope I can get it sorted out.

I'm so glad I didn't buy my MM with a sunroof. I was having a difficult time finding a silver 04 withOUT a sunroof that I almost gave up and bought one with a sunroof.

I ordered a set of factory manuals so hopefully they will have a good flow chart on a/c diagnosis.

Steve

Bradley G

07-30-2006, 08:14 PM

I think I read a TSB on panthers, that stated complaints, of ice particles/snow comming from the vents.

My Marquis 2002 will freeze you out!
Wonder why the(some) Marauders' a/c output is weak.
Let us know what you find out, Shelby
I logged a complaint with the dealer, did not get far.

ShelbyMotorspts

08-02-2006, 04:42 PM

83 degrees outside today and the best I can get the a/c to do is 50 degrees at the registers.

I'm using two separate a/c thermometers and they both read the same.

If something doesn't turn up as being wrong I'm going to have to say this is the worst car I've ever owned when it comes to the a/c.

UPS just delivered the factory GM service manuals so time to start doing some reading.

Steve

GreekGod

08-02-2006, 05:18 PM

I use an a/c thermometer in my registers. I get 45 degrees most always. My Geo Metro convertible with a black top had better a/c!
83 degrees outside today and the best I can get the a/c to do is 50 degrees at the registers.

I'm using two separate a/c thermometers and they both read the same.

If something doesn't turn up as being wrong I'm going to have to say this is the worst car I've ever owned when it comes to the a/c.

UPS just delivered the factory GM service manuals so time to start doing some reading.

Steve

ShelbyMotorspts

08-02-2006, 08:36 PM

Well last week the dealer replaced the orifice tube because they said the low side was reading too high at 50psi.

After they replaced the orifice tube they said everything was fine with new readings of 175 high 30 low. But my a/c output is still poor.

So tonight I'm reading the factory service manual and it shows that the 175 high and 30 low pressures are both out of range for 92 degree weather.

The manual shows for 92 degree weather the high should be between 195-310 psi and the low side should be between 44-61 psi.

Averaging out these factory book numbers comes to 253 high and 53 low. So how can they say everything is good at readings of 175 high and 30 low?

Yes the car needs to go back but I want to be better prepared this time.

Any thoughts on the current 175/30 readings on an 92 degree day?

Steve

ShelbyMotorspts

08-04-2006, 12:00 PM

Anybody???

Bluerauder

08-04-2006, 12:46 PM

Anybody???
Here's a response that Smokie posted when I was having similar problems back on 10 June 2005. Sure sounds like your reading are low on both sides.

I know A/C. First off it is very unlikely that your vent puts out 32 degree air since that is the temp at which water freezes, 36-40 degrees on an 85* day with high humidity would be normal. I recommend you buy a pocket thermometer such as the ones A/C tecnicians use and put it in the vent (they are inexpensive and very accurate)

Does your A/C produce water that drips under car while A/C is running? It should.
Does your suction line going back to compressor sweat and it is very cold to the touch? It should. (Suction line is the larger diameter hose or pipe from the outlet of the evaporator back to compressor)

Don't have someone just tell you the pressure is ok, ask if they are checking both the low side and high side and ask what those pressures are.

Typical hot day your high side should be between 190--250 psi, your low side at a high idle should be no less than 35 psi and no more than 45 psi. Good luck.

P.S. Freon does not wear out, if freon was added to your system YOU HAVE A LEAK. it is illegal in Fl. to recharge a leaky system, it must be repaired (find and Fix the leak)

ShelbyMotorspts

08-04-2006, 01:12 PM

Here's a response that Smokie posted when I was having similar problems back on 10 June 2005. Sure sounds like your reading are low on both sides.

Bluerauder

Yup found that post when I was searching the archives. Also found a post from Rheinhardt (sp?) that I think agreed that my pressure readings are not correct.

After getting the factory service manual that says both my high & low pressures are out of the "normal range" we can conclude that I have a problem.

I guess my question is what would cause the high pressure and the low pressure readings both to be reading too low?

Steve

Dr Caleb

08-04-2006, 01:18 PM

I guess my question is what would cause the high pressure and the low pressure readings both to be reading too low?

Steve

W.A.G. says the evaporator. If it's clogged, the high pressure side will be too high, the low side too low.

ShelbyMotorspts

08-04-2006, 01:25 PM

W.A.G. says the evaporator. If it's clogged, the high pressure side will be too high, the low side too low.

But my high pressure along with my low pressure are both reading too low.

What's W.A.G. ?

Steve

Dr Caleb

08-04-2006, 02:05 PM

What's W.A.G. ?

Steve

Wild Assed Guess.

In that case, I'd WAG the compressor.

JMan

08-05-2006, 03:37 AM

Shelby,
Low refrigerant level (Not enough) would give those readings and the symptoms you describe. It may also cool better at idle than at road speeds due to the nature of the system. If the refrigerant pressure gets too low on the low side, the compressor shuts off to keep the evaporator from freezing up. At higher speeds - say 1500rpm as opposed to idle - the compressor is doing more pumping and the low side drops off quickly to a sub-freezing pressure. At that point, the cycling switch breaks contact and the compressor shuts off. However, at idle with the windows up in the shade of a service bay on Max A/C and a low blower speed, it would seemingly be fine! Park that same car in the Florida sun for an hour and it isn't gonna cut it on the ride home.

Lastly, don't expect an automatic temperature controlled system to blow 40 degrees from the vents on automatic settings. The lowest available temperature on "Auto" is 60 degrees. Once the cabin temp reachs 60 as determined by the return sensor in the dash, it starts modifying the vent controls. Use the "Max" setting and a medium blower for reading the lowest attainable temperature at the vents. Also make sure the windows are rolled up.

Best luck,

J

ShelbyMotorspts

08-05-2006, 12:40 PM

J, Thank you for the input.

I only wish the interior temp was reaching 60 degrees and the ATC was adjusting things.

The backseat passengers all complain that there is no a/c back there and while I haven't been in the backseat I have to agree that it must be bad since the front barely cools. Sorry folks the backseat people are family so I can't just tell them to be quiet.

Last Thursday was the first overcast day we have had here in SoCal for sometime and the problem exists even in mild weather. 73 degrees outside and the best I can get from the vents is 50 degrees.

As previously mentioned this is in a Silver MM, NO sunroof and with window tint applied to all windows except for the w/s.

I have noticed that the engine has a fair amount of corrosion on it and have been meaning to check the a/c condensor to see if it looks as bad as the engine. I'm thinking that if the condensor has corrosion like the engine possibly the corrosion is acting like insulation and is not leting the condensor do its job.

Steve

Smokie

08-05-2006, 01:09 PM

Have you checked the things I suggested? I would not suspect the problem being the condenser, it is the most durable part of your entire seal system.

Sixty degree output from vent is bad, I just went outside and checked vent output temps.

Black MM., tinted glass, parked in driveway, full sun exposure, ambient 93 degrees, outside temp. reading 97 degrees, engine at 1500 rpms in Park.

Vent temps. average of all 4 vents 37 degrees. A/C at MAX A/C 60 degrees, fan in highest speed setting.

Measuring device: Raytek MiniTemp infrared thermometer held 3-5" away from vent, laser sighting aiming at interior of vent.

Top of Dash temperature 127 degrees.

ShelbyMotorspts

08-05-2006, 01:45 PM

Have you checked the things I suggested? I would not suspect the problem being the condenser, it is the most durable part of your entire seal system.

Smokie

I was able to check some items you mentioned but things like the pressures I have not. I do have a set of a/c gauges somehwere but I'm pretty sure they have the r-12 fittings. Time to go buy some adapter fittings for the r-134.

I took off that black plastic cover in the engine compartment that covers the radiator & condensor. Didn't see any corrosion so they must coat the aluminum fins with something to prevent that. There is a minimum amount of leaves, feathers, dirt on both the condensor & radiator so later today I'll take the radiator fan shroud off and backflush them both to remove the debris. But overall they look good and like you said probably not the problem.

My MM is still new to me so forgive me for what might seem like stupid questions it's just because I haven't spent much time under the hood yet.

Do our cars use a heater control valve in the heater hose? If they do possibly it's not closing all the way and is sending some hot coolant to the heater core which the a/c system has to try to cool back down. Just a thought I had.

Steve

Smokie

08-05-2006, 01:58 PM

...Do our cars use a heater control valve in the heater hose? If they do possibly it's not closing all the way and is sending some hot coolant to the heater core which the a/c system has to try to cool back down. Just a thought I had.

Steve

Obviously there is a valve the controls the flow of coolant into the heater core, I don't know where is located; your thought is a good one. One way to check would be to turn on the Vent setting to coolest setting, if it blows HOT air while driving that would answer your question.

ShelbyMotorspts

08-05-2006, 08:30 PM

Took a look under the hood tonight and couldn't find any sort of heater control valve in either heater hose.

Pulled out the shop manual and it looks like the heater core always has hot coolant flowing thru it and that the temperature blend door controls how much heat is added to the cabin air flow thru the vents.

I had the EATC module run a self test and no trouble codes came up on the display. The manual shows that this temp blend door is activated by an electric motor and if it wasn't working it would show a trouble code.

So it doesn't look like the heater core is causing any trouble.

wchain

08-08-2006, 02:24 PM

I think we're all missing something here.

Shelby, if you car is so new, there is something wrong thats causing the orifice tube to become clogged. I.e. trash in the system of some sort.

I just did a Texas tune up on a 98 CVPI (Compressor, Accumilator Drier, O-Rings and Orifice Tube) and the tube was nowhere near clogged, but I installed one anyway (they cost less than 3 dollars).

When the dealer stated that the orifice tube was clogged, you need to ask what was causing it to clog, is the compressor eating itself from the inside?

The other thing to consider, how dirty is your condensor? How about checking the amount of junk behind the grille, as well as between the radiator and the condenser.

If the dealer opened up your system, did they replace the accumulator/drier at the same time? It is recommended that it be replaced any time the system is opened.

One more thing, some Ford trucks and SUVs had a little valve that was vacuum activated, when the AC was on Max, the acuator got vacuum and actually closed the line off into the heater core, blocking the flow of coolant to it, so the blower was only exposed to Air from the evaporator.

Heater blend doors with the EATCs have been known to split and crack too.
Anyway just my .02.

Good luck.

MENINBLK

08-08-2006, 02:38 PM

I recently had an AC problem.

After 2 years my Condensor had so many pebble nicks in it,
that one actually scored and the R134a all leaked out.
I had it refilled at the dealer along with a dye.
After 3 weeks the AC went dead again.
They found the leak and confirmed the condensor.

Now I've gotten a new condensor and a new orifice tube,
I've also installed Defyant's lower bumper grille mod
to protect the new condensor.

I gotta tell you, just like the day the Marauder was new,
my AC is freezing me out again.
We had a heatwave last week with temps in the lower 100s - 110F !!
I was sooooo happy my AC was working properly.

ShelbyMotorspts

08-08-2006, 03:06 PM

if you car is so new, there is something wrong thats causing the orifice tube to become clogged. I.e. trash in the system of some sort.

In hindsight I think the dealer misdiagnosed the problem when they replaced the orifice tube. The dealer claimed the orifice tube needed replacing because the low pressure read 50 psi.

After buying the factory service manuals I have come to learn that the low pressure should be between 44-61 psi so the dealer was in error saying that 50 psi was bad.

My current plan is to get the car into another dealer but that appointment is two weeks away.

Steve

Smokie

08-08-2006, 06:00 PM

ShelbyMotorspts

08-08-2006, 06:20 PM

You are in my opinion low on refrigerant by more than a little bit.

Thanks Smokie.

I really need to go dig out the set of gauges I have and purchase the r12 to r134 adapters so I can verify the readings first hand.

Will keep everyone informed.

Steve

ShelbyMotorspts

08-10-2006, 01:27 PM

Went out and purchased a set of a/c gauges and here's what I get:

85-90 degree outside weather

Static Pressure is 10-11 psi

45 psi low and 200 psi high at 750rpm
(coldest vent output is 64 degrees)

30 psi low and 275 psi high at 1500rpm
(coldest vent output is 55 degrees)

Ok let the ideas on what is wrong start flowing.

Steve

Smokie

08-10-2006, 03:47 PM

Steve just some things I need to be certain of: Are you on MAX A/C set at 60, highest fan speed?

What kind of thermometer are using?

Is your low side hose returning to compressor "very cold and sweating profusely? The top hose coming out of evaporator has a metal section where the fitting for the low side gauge goes, this should very very, very cold. After that it goes into a black cylinder (reciever) before it goes back to compressor, all this should very, very cold and sweating profusely.

Is there water steady dripping on the ground from the evaporator drain under car?

Is your cooling fan running at full speed, our cars have a single electric fan that moves air thru condenser & radiator, if you are not moving; the electric fan must be working or no air flow.

Your low side is in my opinion a bit low at 1500 rpms and your high side on the high side of normal. I need a little feed back from you to try to help further.

ShelbyMotorspts

08-10-2006, 06:23 PM

Smokie

All tests are with the a/c in the manual mode but not on max/recirculate. The lowest temp the EATC will let me dial in is 65 degrees. I noticed you said 60 degrees and the factory shop manual also says 60 degrees but my EATC display will not go below 65.

I'm using professional a/c thermometers with one of them being electronic. They look like minature meat thermometers.

The car does drip a fair amount of water from the evaporator housing. The one line does indeed sweat.

The electric fan does run.

What concerns me the most right now is the 10 degree vent output difference between when the car is at idle at 750 rpm and the second test I performed at 1500 rpm.

The Ford factory shop manual doesn't mention anything about holding the rpm's at 1500 when taking the gauge readings. It just says with the car running, windows down and the system on normal.

This 10 degree temp difference can be felt changing right when you come to a red light. Besides feeling the change I can watch the thermometer creep up the 10 degrees higher in under a minute. Remember at idle the coldest air I can get out of the vents is 60-64 degrees when others here are saying they get under 40 degree temps from their MM.

Does the static pressure of about 10 psi sound ok? I looked in the service manual but didn't see any specs on what the static pressure should be.

Steve

Eric91Z

08-11-2006, 04:16 AM

I know my car runs much cooler or seems to take less effort to keep the car cool at highway speeds than it does driving around town with lots of stop and go. But, even with out recent 90-100 degree temps, I would let the car run a couple minutes (2-3) before going out of work and getting in the car. Then hop in, drive about 2 blocks and get on the interstate. Byt the time I am merging with traffic I can feel the car cooling down. Then by the time I get on the next interstate (2 miles or so), the car is cool, I turn the temp down to 65-68 range (from the 60 I start it at) and turn the fan down.

I do hope you can get your A/C issues resolved. I do so enjoy a car with tinted windows and working A/C. The car has been a pleasure to drive this summer compared to any other car I have ever owned. Only other thing I could ask for is ventilated seats to cool my butt and back while driving (something like the Navagator has). Doesn't matter what car I am in or what seat material, my back will always get a little sweaty even if the interior temp is nice and comfortable.

Smokie

08-11-2006, 04:23 AM

I had a power failure last night, I hope you meant "windows closed" not windows down normal a/c at 65 will blend some outside air.

Do your checking on max a/c, the button to the far left, my CrownVic and Marauder both go to 60 I don't know why your does not.

It is normal for pressure on low side to drop when you increase rpms, that is why I wanted you to check at higher then idle to make sure you are not low on gas if you are holding at least 30-35 on low side at 1500 rpms and your suction line is very cold and sweating all the way back to compressor I suspect your head unit is mixing outside air when it's not supposed to or air from heater core is mixing with cold air.

I have to go to work now, well check in later.

ShelbyMotorspts

08-11-2006, 10:31 AM

Smokie

Yes windows down/open just like the service manual says to do with the recirculate/max off.

I'll go take some temp readings with the windows closed and the system on recirculate. Will post the results here.

Steve

ShelbyMotorspts

08-11-2006, 01:06 PM

First off my EATC does indeed go to 60 degrees.

On the freeway with the cruise set at 70 mph, the engine turning a steady 2000 rpms and the outside temp being 85 degrees I get these temps from the vents:

Normal a/c is 45-49 degrees

Max/recirculate is 44-47 degrees

So even with excellent airflow thru the condensor at 70 mph the best I can get is 44 degrees which may sound cold but compared to other cars I've owned it isn't.

Since others here have posted that they get vent temps in the mid 30's I have to believe something is just not right with my system.

Steve

Smokie

08-11-2006, 02:41 PM

I agree something is wrong, I can't be sure if you are low on gas or somehow outside or warm air is mixing with your cold air. Your vent outlet temps are 8-10 degrees too warm.

Here is a suggestion to rule out being low on gas:
Buy a 1 pound can of R-134 and adapter for gauges.
What I reccommend is slowly adding gas while you are monotoring the effect on the outlet vent temperature.

Choose hottest part of day to do this, to avoid losing gas and refrigerant oil connect and disconnect the high side when a/c is off (after you ran a/c wait a few minutes for pressure to drop), low side connect and disconnect when engine is running-a/c on.

After you have gauges connected, thermometer in center-right vent, Max a/c-(set at 60) highest fan speed, windows CLOSED run at least 5 minutes to allow temp in car to stabilize.

Notice what your pressures are at idle and vent outlet temp. connect R-134 can to charging hose (make sure your gauge valves are shut) open valve at can, keep upright and purge air out of charging hose at gauge end (this is very important, so you don't put air/moisture in your system) by slowly loosening charging hose connector and letting a little gas escape.

Have a friend maintain your rpms at 1000 and monitor vent outlet temp as you let gas (upright can) into system, you want to increase your low side maybe 5 psi no more and see if it has a cooling effect on your vent outlet temp.

If you need gas, adding 2-3 ounces will lower your outlet temp. this can take about 1 minute after adding gas is not instant. if adding gas has a positive effect on vent outlet temp. continue slowly adding gas until outlet temp drops below 40. If you add 3-4 ounces and there is no lowering of outlet temps STOP because the problem is elsewhere.

Don't forget to monitor your high side temp. and make sure it does not exceed 350 psi (ambient temp 85-90)

I hope this helps some.

JACook

08-11-2006, 10:03 PM

30 psi low and 275 psi high at 1500rpm
(coldest vent output is 55 degrees)
Those pressures look more or less normal for R134a systems. But there is one vital piece of information missing-
What was the ambient temperature at the condenser? Your high side readings are a bit high, suggesting the
condensor was pretty hot. The radiator fan was running, yes? Any missing shrouds/seals between the fan and
condenser that could be causing an air leak? One of the most common causes of poor A/C system performance
is inadequate airflow across the condenser. If you spray water on the condenser, you'll see the pressures drop.
See if that causes your vent temps to drop as well.

The "black death" problem was pretty much confined to the FX15 series compressors. The FX15 was replaced
by the FS10 around 1993. The MM has a newer scroll design. Don't recall the number, though.

The numbers you see in the shop manual are guidelines. High and low side pressures are strongly influenced by
ambient temperature, and humidity. Your gauge set should have come with a temperature/pressure chart for
R12 and R134a. Using this chart, you should be able to see that 30PSI equates to about 35 degrees F.

Is your compressor cycling? If it doesn't cycle at idle, but does cycle at 1500 RPM, you're likely low on charge.
I usually like to adjust LPCO (low pressure cutoff) switches to cycle the compressor at closer to 25PSI with
R134a, but the LPCO switch on the MM does not appear to be adjustable.

If it's not cycling, I'd start by comparing the temperatures of the refrigerant lines going into and out of the
evaporator. The MM uses what's known as a "flooded evaporator" type of system. When the system is
properly charged, the tube leading out of the evaporator into the accumulator should be about the same
temperature as the tube leading into the evaporator from the orifice tube. The accumulator gives any
remaining liquid refrigerant a place to expand, so that the compressor doesn't get slugged. (Compressors
do not like to inhale liquid...)

If the outlet tube from the evaporator is noticeably warmer, you're either undercharged, or depending on
system airflow design, it could be a blend door problem. If the outlet tube from the evaporator is nice and
frosty, but your vents are warm, I'd definitely suspect a blend door problem. I don't believe the MM has
a heater shutoff valve. It's all done by managing airflow.

Using a hose clamping tool, you can pinch off the supply line to the heater core (the smallest of the 3 hoses
attached to the coolant crossover pipe). If your vent temps drop, you've likely got something wrong with the
blend door, or some other airflow management problem. These may not show up as an EATC trouble code.

Where in SoCal are you located? I'm in Garden Grove, and would be happy to put the eyeball (and my gauges)
on your MM. But it'll have to wait a couple weeks. Going on a couple back-to-back road trips...

ShelbyMotorspts

08-12-2006, 12:04 PM

Smokie & JA thanks for the tips. Sooner or later we'll find the problem.

I'm not sure if the compressor is cycling at idle. I'll have to check that closer. I know it's cycling at higher rpm's because I can see the vent output temps change by 3-4 degrees.

On other cars I've owned I've always been able to tell when the compressor cycles because I can hear the clutch engage and/or the engine rpm's change. On my MM I can't hear the clutch engage nor do I see the rpm's change.

I'll try to get some temp readings from the evaporator lines and that blend door has been on my mind.

Steve

ShelbyMotorspts

08-12-2006, 01:05 PM

As far as I can tell the compressor is not cycling at idle.

I tried to get my thermometer probe on the evaporator lines but just couldn't make good enough contact on the lines for an accurate reading. I'll have to go buy one of those infrared guns.

I did notice that the bottom evaporator line (smaller diameter one) did feel warmer compared to the top evaporator line (larger diameter one).

Steve

ShelbyMotorspts

08-12-2006, 03:36 PM

Went out and purchased one of those infrared laser thermometers but can not get a temp reading on the evaporator lines.

Tried up close, far away and in between but it keeps picking up the heat from the exhaust manifold.

It still seems like the upper larger hose/pipe is much colder than the lower smaller hose/pipe to the touch of my hand.

I again looked thru the factory service manual and can find no spec for the static system charge pressure. I'm getting 10 psi reading. Does anyone know what their static pressure reading is?

Steve

JACook

08-12-2006, 09:37 PM

I again looked thru the factory service manual and can find no spec for the static system charge pressure. I'm getting 10 psi reading. Does anyone know what their static pressure reading is?

I saw this before, and kinda glossed over it, thinking it was a typo. By static pressure, I'm presuming you
to mean both sides equalized, compressor not running. Unless the ambient temperature in SoCal was about
7 degrees recently, 10PSI is really low. And if the pressure was really that low, your compressor clutch
would never kick in, unless someone bypassed the LPCO switch. Something's not quite right here.
Maybe I'm misunderstanding what you're trying to describe?

The shop manual doesn't really concern itself with static pressure, since that will depend completely on
ambient temperature, and the type of refrigerant used. Unless you're extremely undercharged, or overcharged,
static pressure is not an indicator of system charge.

If you were to measure a can of R134a off the shelf, at the same ambient temperature as your MM, the
pressure should be the same. And it should agree with the temperature/pressure chart for R134a at
your ambient temperature.

Your temperature differential into and out of the evaporator is consistent with the high vent temps you're
seeing. Just need to figure out why. Don't worry too much about how to measure this, for the purposes
of what we're doing here, your hands are accurate enough.

Since this problem existed before the O-tube was replaced, I'm thinking it has something to do with the
heater core and blend door. This would also cause the low side pressures to be higher than they should,
in a properly charged system. You need to eliminate the heater core as I described before going any farther.
If you do this, and the vent temps improve, you probably now have two problems. The original blend door
problem, and if the shop charged according to low-side pressures, you're now undercharged as well.

The proper way to charge a system is to vacuum it down, and then charge by weight, according to the
manufacturers specs. This will get the proper amount of refrigerant into the system so that it performs
exactly as designed. There are other methods that will get good results, but charging by weight will also
let you know when something isn't right with the system.

Also still need to know if the compressor cycles at 1500 RPM.

Smokie

08-12-2006, 10:32 PM

Steve I agree with Jeff that pinching off the heater core inlet hose is about the fastest and easiest way to rule out a blending door problem.

He is also correct that the ideal way to charge is to vacuum down the system and charge by exact specified weight, however is not the easiest way to go about it and it will require you to gain access to a vacuum pump and charging panel. You have my suggestion on how to see if a few ounces of gas is all you need.

You keep asking about static pressure and I am not sure what you are talking about because it is a term that I am more familiar with in measuring the output of a fan across a coil, I have never used any devise that measures static pressure to charge a car or residential A/C. I simply don't know what you are measuring when you say 10 psi, unless you are talking about the difference between your reading on your low side and high side with the A/C off,

If that is what you are referring to, it could simply be due to both your gauges not being properly zeroed before you hook'em up.

ShelbyMotorspts

08-13-2006, 01:33 PM

Regarding static pressure:

Engine off, high & low gauge set hoses connected, center fill/yellow hose put in a loop and both valves opened on the gauge set. Yes I know static pressure on it's own doesn't say much but I was hoping to compare the 10 psi I get with another MM.

It's time to start looking at the blend door. The service manual talks about removing the dash to get to it so pinching off the heater hose will be much easier.

I do have cans of R134a and also have a vac pump but because the car is under warranty I've been hesitant to add any refrigerant. If it needs refrigerant that means there is a leak and I would prefer having any leaks repaired under warranty.

Do you guys get the same 10 degree vent temp difference that I get?
Remember at idle the best vent temps I can get are 10 degrees warmer compared to the temps at 1500 rpm.

Also the radiator fan seems to have multiple speeds. Is this correct?

Steve

Smokie

08-13-2006, 01:50 PM

Hang on I''ll go check.

Smokie

08-13-2006, 02:15 PM

This is what I have:
Current temp: 93 degrees
Humidity: 57%
Feels like temp: 104 degrees

Car parked at full sun exposure, Outside vent reading is 97 degrees.
Top of dash temp reading before starting car: 158 degrees.
Start car set at MAX A/C (60) highest fan speed and wait exactly 4 minutes before taking reading (windows are closed)

Average vent reading (infrared held 3" from vent) 34-36 degrees at idle in Park (for my car this is 900 rpms)

Average vent reading same method at 1500 rpms 30-32 degrees.

Top of dash reading after 5 minutes 116 degrees.

Smokie

08-13-2006, 03:11 PM

Some additional info, may help may not. If you are going to check with your fingertips the difference in temperature between the evaporator inlet tube (bottom line) and the outlet tube (upper line).

Make sure you let the A/C run a few minutes and check the lower line between the evap. housing and supporting line braket (room for about 2 fingers) because this is AFTER the orifice tube, notice the dimples in line holding orifice in place. The condenser side of orifice will be warm but should not burn you.

My A/C works well and the upper and lower lines are NOT equally cold, but they are both cold, the upper line is colder and sweats profusely the lower one does not. I don't believe is possible for both to be equally cold because right after the orifice there is low pressure liquid and the smaller diameter of the lower line does not allow the same amount of expansion (boiling) of the gas as the larger diameter upper line.

I hope all this info is not causing more confusion than good.:)

ShelbyMotorspts

08-16-2006, 02:54 PM

Picked up the MM from the SVT Ford dealer this morning and no improvment in the a/c output. Tech says no problem found. I kind of expected this answer as the temps here in SoCal are back to normal compared to the last few weeks.

I took some more readings/measurements today:

Outside temp 76 degrees.

Vent temps: 53 degrees at idle
Vent temps: 47 degrees at 1500 rpm

High Pressure at idle: 200 psi
Low Pressure at idle: 45 psi

High Pressure at 1500 rpm: 255 psi
Low Pressure at 1500 rpm: 28 psi

Vent Temps at 70 mph (2000 rpm): 45 normal a/c
Vent Temps at 70 mph (2000 rpm): 43 max/recirc

I could be wrong but at idle the electric radiator fan doesn't seem to run that fast and I can't see the a/c compressor cycling. When the compressor cycles off shouldn't I see the a/c clutch stand still?

Steve

I did pinch off the upper heater hose and saw no difference but that doesn't mean I've given up on the blend door as a possible problem.

Smokie

08-16-2006, 03:44 PM

Your pressures seem normal to me for 76 ambient, your vent temps remain high, try spraying your condenser with water and check vent temps.

I know you are still under warranty and you don't want to add gas...without being there I don't know what else to suggest.

Do you live near another MM. owner that you can compare vent temps and pressures??? Even a CrownVic or Grand Marquis will do, the a/c is the same.

BAD MERC

08-16-2006, 03:54 PM

I think I will take mine to Germain L/M for a second opinion. Even on a 90 degree day, my back is saturated with sweat, the seats (light flint) feel like the heaters are on and I need to point the vents right on my face or even up my pants leg just to get it tolerable. Tinted all the way around AND the whole windshield. I have remote start and the car never gets comfortable except at night when there is no sun load. Christ, the A/C on my motorcycle was better than this!

ShelbyMotorspts

08-16-2006, 04:28 PM

Smokie

I'll try the water on the condensor. How much water? Full blast from a garden hose or just a misting?

The SVT dealer receipt claims that they discharged and recharged the system so you would think that the refrigerant is at the correct amount.

Yeah I tried to hook up with any other SoCal MM's but my post went unanswered. I have been thinking of going to the dealer and test driving either a GM or a CV to see how well their a/c works although I've been hesitant because it's not fair to the salesperson as I have no intent on buying their car.

This is getting frustrating and just this afternoon I had my first thought of selling the MM. It's still 76 degrees outside, I'm parked completely in the shade waiting on family to come out of the store and the best this car can do is 57 degrees from the vent which is only a 19 degree difference from the outside temps.

Arrgggghhhh..........

Steve

ShelbyMotorspts

08-16-2006, 04:32 PM

Silver2004

I feel your pain as I can't even picture driving my MM in Florida. I'm starting to believe that these cars just have a poorly designed a/c system but people like Smokie and others have kept me going and not giving up just yet.

Steve

Smokie

08-16-2006, 04:44 PM

"Where in SoCal are you located? I'm in Garden Grove, and would be happy to put the eyeball (and my gauges)
on your MM. But it'll have to wait a couple weeks. Going on a couple back-to-back road trips..."__________________
Cheers,
Jeff Cook

I don't know if you noticed^^^^^ this offer.

A spray a mist or shower spray and just check to see if you vent temps drop, don't worry too much about the high side dropping...it will for sure. You just want to see if the vent temp drops to the 30's.

Florida has been brutally hot and humid lately and the truth is both my 95 CrownVic and my Marauder keep me very comfortable and my passengers in the rear seat also.

ShelbyMotorspts

08-16-2006, 04:46 PM

Smokie

What about the a/c compressor cycling at idle. Shouldn't I see the clutch stop rotating?

Steve

Smokie

08-16-2006, 05:08 PM

ShelbyMotorspts

08-16-2006, 06:05 PM

Cycling on and off is normal as long as is not happening like every couple of seconds and it it should be on longer intervals than off, if it stays off prolonged periods of time, it ussually means your are low on gas or have a clogged orifice tube.

The clutch does stop turning when it cycles off.

Yes on & off is normal but I sure don't see that happening at idle. After 2-3 minutes I got tired of watching the clutch without it disengaging so I gave up. I'll have to look at it some more.

Steve

ShelbyMotorspts

08-17-2006, 10:54 AM

Ok more tests & more ideas. First off the outside temp is 67 degrees so for sure I'll get some nice cold vent readings right? Nope same problem even on a mild 67 degree day.

Did what Smokie asked and sprayed the condensor with water. No change on the vent temps with the slight possibility the vent temps increased by one or two degrees.

67 degree outside weather, a/c on normal and the lowest vent temp I can get at idle is 56 degrees. Something can't be right. 56 degree a/c output on a 67 degree day is horrible.

While doing the water on the condensor test I again noticed that the a/c compressor does NOT cycleon & off at idle. I stood there and stared at the clutch for over five minutes and not once did it cycle off.

Why is the compressor not cycling on & off?

Steve

Smokie

08-17-2006, 11:05 AM

I know you are frustrated by now, you said the first time you took it in the orifice was replaced. Why? a clogged orifice tube is the result of a bad compressor or so much moisture in the system it ices up.

In your shoes I would add a small amount of freon and see if vent temps drop.

Check calibration on your thermometer with a "glass" filled with ice an just enough water to cover all the ice. Your thermometer should read 32-33 degrees No higher.

You need to get your thermometer in the vent of a new C/V-GM at the dealership and compare outlet temps. Vent temps in the mid 40's and 50's is just plain crap. Go for a test drive in a new car if you have to...no more mr. nice guy.

ShelbyMotorspts

08-17-2006, 11:53 AM

I know you are frustrated by now, you said the first time you took it in the orifice was replaced. Why? a clogged orifice tube is the result of a bad compressor or so much moisture in the system it ices up.

Smokie

The first time I took it in to the L/M dealer I was so happy that they found a problem that I didn't bother to ask any questions when they called and said it was ready. I just figured I was going to get a car back with ice cold a/c that I saw no reason to ask for detailed info.

This is the part # on the service receipt for the orifice tube: F5DZ19D990AB
Does anyone know if this is the right orifice tube?

All of us also need to always keep in mind that when it comes to warranty work dealers have been known to say they replaced something when they didn't just so they can get a higher reimbursement from Ford. I'm not saying the first dealer did this but I also do not have proof that they changed the orifice tube.

Would someone here go see if their a/c compressor cycles on & off at idle. Mine doesn't and I can't recall ever owning a car that doesn't sit there and cycle on & off at idle.

Steve

kj31067

08-17-2006, 12:13 PM

i know mine does in drive with my foot on brake cause i hear the chirp when it does kick on........

GreekGod

08-17-2006, 12:51 PM

It is time to contact your Ford zone representitive or whatever they call them nowadays. If your dealer's service fails, go over their head.

It is their baby. No need to add refrigerant. MAKE them fix it.

I seem to have the same problem you do but haven't been into my dealer yet. A/C shouldn't be so difficult to repair.

BAD MERC

08-17-2006, 01:09 PM

Thanks man, my 1995 Taurus would get uncomfortably cold inside and I occasionally had to turn the fan almost off because it made my knees hurt. For a $38,000 car, the Marauder should have an ice-maker in the dash.
Silver2004

I feel your pain as I can't even picture driving my MM in Florida. I'm starting to believe that these cars just have a poorly designed a/c system but people like Smokie and others have kept me going and not giving up just yet.

Steve

Marauderjack

08-17-2006, 02:30 PM

ShelbyMotorspts

08-17-2006, 03:40 PM

I have had a problem with my air and it was that the compressor was ON ALL THE TIME!!!:argue: I just about froze to death until the whole thing froze up and no air was coming out of the vents!!:mad2:

Turning it off did nothing....so I went to the Ford dealer in Columbia, SC and they worked me in.....after about an hour they came back with the car and it was the compressor relay that failed.....about $100.00 total but it was covered by warranty!!:beer:

Perhaps you have the same problem since the compressor isn't cycling??:confused:

Marauderjack

MJ

Thank you for posting your experience. Right now I plan on going back to the SVT dealer on Friday and forcing either the service writer or the mechanic to take a ride with me so they can see how bad it is.

After that if they still say everythings fine then it's time to ask them to get a Panther off their lot and we will go for another ride. If their car does the same as mine, meaning 50 degree vent temps on a mid 60 degree day, then there will be a real nice 04 MM for sale.

Now if their car cools better than my MM I'm going to be asking them to start replacing parts until it's fixed.

Steve

GreekGod

08-17-2006, 05:16 PM

It seems the "service" from your dealer amounts to parts replacing.

Now if their car cools better than my MM I'm going to be asking them to start replacing parts until it's fixed.

Bluerauder

08-17-2006, 05:29 PM

It seems the "service" from your dealer amounts to parts replacing.
There's alot of that going around. It's getting rare to find a real mechanic anymore. :o

ShelbyMotorspts

08-18-2006, 02:16 PM

Good and bad news today. The good news is it appears nothing is wrong with my a/c. The bad news is the a/c sucks on these cars.
<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comhttp://www.mercurymarauder.net/forums/<o:p></o:p>
Went back to the SVT dealer today. Outside temp was 78 degrees and the best the car could do on the freeway cruising at 70mph is 47 degrees from the vent. At idle the vent temps creep up to 50-51 degrees.<o:p></o:p>
<o:p></o:p>
Basically the SVT dealer said nothing is wrong and that a 30 degree temp difference from the outside temp compared to the a/c vent temp is the standard Ford uses for a/c performance. Of course the car is in the shade of the service bay and of course they put the a/c on recirculate to barely reach this 30 degree difference.<o:p></o:p>
<o:p></o:p>
So I leave the SVT dealer and go back to the L/M dealer who replaced the orifice tube a few weeks back. I show them that the coldest it will get is 50 degrees at idle and at first they were agreeing that 50 degrees did seem a little on the warm side. They wanted me to bring it back next week when the a/c tech would be back from vacation.<o:p></o:p>
<o:p></o:p>
It took a little effort but I was able to convince the service writer to go with me to the new car lot and lets see what a 2006 GM would do at idle. The best we could get this brand new GM to put out at idle was 52 degrees and that was on max/recirculate. Arrgghh!!<o:p></o:p>
<o:p></o:p>
I was hoping the 06 GM would put out ice cubes so that I could just say make mine work like that but after 10 minutes this 06 GM couldn't do any better than 52 degrees.<o:p></o:p>
<o:p></o:p>
So in a nutshell it appears these a/c systems just suck. How you black MM owners deal with it I have no idea but I still hope to meet up with another MM owner so we can do a car to car comparison on the a/c output.<o:p></o:p>
<o:p></o:p>
Steve<o:p></o:p>
<o:p></o:p>
PS- Thank you to everyone who hung in here with me. I know a lot of people were probably bored by this thread but hopefully down the road someone else will find the info we all posted helpful.<o:p></o:p>

Smokie

08-18-2006, 03:19 PM

I'm sorry it turns out there is nothing wrong with 50 degree vent temps, I have a black MM in central Florida, mine makes the interior of the car more than just comfortable...it makes it cold enough where you have to turn down the fan.

My brother in law has a 1970 Mustang with a real crappy A/C that needs a new condenser, we both agree the A/C sucks, guess what his vent temps are on a hot day....50 degrees.;)

ShelbyMotorspts

08-18-2006, 06:36 PM

My brother in law has a 1970 Mustang with a real crappy A/C that needs a new condenser, we both agree the A/C sucks, guess what his vent temps are on a hot day....50 degrees.;)

Smokie

I wish I could get 50 degrees from the vents on a hot day. Being in Florida I'm sure you know that our 78 degree weather today is not hot at all.

Remember a week or two ago I was only able to get 60 degree vent temps on a 90 degree day but that matches the 30 degree temp difference Ford says is normal.

I do hope to hook up with another MM owner just for a final comparison
and then it's time to hit up the a/c boards to see how I can improve a poorly designed system.

A few ideas bouncing around in my head are a pusher fan mounted on the front of the condensor for more air flow at idle and maybe trying a different size orifice tube.

Might help might not but at least I tried something to make it perform better.

Steve

Marauderjack

08-19-2006, 09:09 AM

Just for kicks I put a lab thermometer in my A/C vent and guess what.....50* was about the best I saw under normal conditions and 45* with it in "MAX" and temp turned down to 65*??:eek: I would have sworn it was colder but maybe this is about all the 134a can do?? R-12 would take temps down into the 30's!!:beer:

Mine keeps the car plenty cold enough even in 100* Wx but I was still surprised the vents only reach about 50*!!:eek:

I guess it helps that my car is silver!!!:bows:

Marauderjack:bandit:

Smokie

08-19-2006, 10:43 AM

I'm becoming a little concerned about the vent readings because what instrument is used and where is placed can greatly influence the reading.

I went outside and took readings on both My 95'CrownVic & MM. but I used the digital therm. that I use at work to calibrate ovens, it has a thermistor tipped flexible probe I placed in the vents.

Results: C/V lowest reading 50*, MM. lowest reading 52*

I also used the infrared point and shoot thermometer and the lowest reading in the C/V was 42*, the lowest reading in the MM. was 34*.

I spent about 5 minutes inside each car and both cars had the same exposure to sun.

The infrared thermometer was telling me the inside of the vents was much colder in the MM.; the digital thermistor probe thermometer was telling me the Crown Vic was colder.

My body was telling me, I was much colder in the MM. than in the CrownVic.

Confusing ain't it???:lol:

Update: I tested both thermometers with a glass filled with crushed ice & water.

Results: digital oven thermometer= 38*
.............Infrared Raytek..............= 32*

My oven thermometer goes to 800* farenheit I suspect is not too accurate at lower temps.

ShelbyMotorspts

08-19-2006, 12:21 PM

Thanks again guys. Your vent temps are basically matching mine and just for fun I'm going to go put the thermometer in the Toyota Avalon to see how it compares.

Steve

JACook

08-19-2006, 02:11 PM

Steve, sorry to see you're still having A/C problems. Since I live near you, I'm not buying the explanation that these
systems just don't perform well. Maybe it doesn't get as hot here in GG, or maybe my expectations are different,
but I can tell you that on a hot day, the A/C in my '03 works plenty well. I've also had my MM in Tucson a couple
times (will be there again this week), and never had any complaints.

To answer one question you asked repeatedly, that didn't appear to get answered, no, your compressor should
not cycle at idle. If it does, you're way undercharged. I would, however, expect it to cycle occasionally at cruise
RPM, as the evaporator chills, and low-side pressures drop.

I also think Smokie is on to something WRT your vent temps. Depending on where you measure, and what you use
to measure, these can vary quite a lot. Assuming your gauges are reasonably accurate, your low-side pressure
readings are telling you exactly how cold the evaporator is running. If you take the low-side pressures you posted,
and compare them to a temperature/pressure chart, you will see that at 27PSI, the refrigerant in the evaporator
core is ~31 degrees. Should be cold enough, as long as you have adequate airflow through the evaporator, and
as long as the system isn't picking up heat from somewhere else.

Understand too, if the blend door isn't working properly, even though you pinch off the hose to the heater core,
the blend door could still be diverting air flow around the evaporator, reducing it's ability to cool the air. It's
also possible that if the system is improperly trying to stabilize at a higher temperature than it should, closing
off the flow to the heater core could simply be causing it to divert even more air around the evaporator. If
this were true, I'd expect pinching off the coolant supply to the heater core would make some difference, but
would not totally solve the problem.

Your shop manual should have a diagram of how things are laid out in the A/C system. Start with the presumption
that the evaporator is running at 31 degrees, and work from there.

Do all your testing with the A/C set on Max recirc, high fan, and engine at 1500RPM.

ShelbyMotorspts

08-19-2006, 06:56 PM

Jeff

Thanks for clearing up the compressor not cycling at idle question. I've never owned a car that didn't cycle at idle so I thought it was strange when I didn't see my MM cycle on & off at idle.

After testing that 2006 GM yesterday and watching it barely match my vent temps at idle I had to concede that my system is working as designed.

I'll be down in LaHabra again on September 7th in the late afternoon/early evening which isn't too far from GG. If you're available perhaps we can meet somewhere for a quick a/c comparasion.

Steve

Smokie

08-20-2006, 06:13 AM

We have analized this thing to death, it's much hotter in other parts of the country than your location and to say that the MM. has a poor A/C system is just not accurate.

Do you own or regularly ride in other vehicles that make you feel cool and comfortable and you consider to have a good A/C system??? If the answer is yes, than there is a problem with your MM.; however this can't be said to be an inherent across the board problem with all MM.s.

Are your passengers in your MM. also feel uncomfortable with the cooling or lack thereof in your MM.???

ShelbyMotorspts

08-20-2006, 12:17 PM

We have analized this thing to death, it's much hotter in other parts of the country than your location and to say that the MM. has a poor A/C system is just not accurate.

But Smokie a brand new GM couldn't do any better than my MM which kind of rules out mine having a problem.

Yesterday we came home and parked the MM and immediately got in the Toyota Avalon. Guess what it's a/c output was? 38 degrees.

Quite a big difference from the MM and shows that R134A systems can put out cold temps.

Hopefully I can meet up with Jeff Cook so we can do a MM vs MM a/c comparasion. Until I see another MM or GM put out colder temps right next to my MM I'll have to stick with the conclusion that this is a poorly designed system.

Don't forget that I drove a 1995 Mercury Sable Wagon for several months and didn't have these complaints. The wagon had more glass area and a larger cabin volume compared to the MM to cool down.

Steve

Smokie

08-20-2006, 03:26 PM

But Smokie a brand new GM couldn't do any better than my MM which kind of rules out mine having a problem.

Yesterday we came home and parked the MM and immediately got in the Toyota Avalon. Guess what it's a/c output was? 38 degrees.

Quite a big difference from the MM and shows that R134A systems can put out cold temps.

Hopefully I can meet up with Jeff Cook so we can do a MM vs MM a/c comparasion. Until I see another MM or GM put out colder temps right next to my MM I'll have to stick with the conclusion that this is a poorly designed system.

Don't forget that I drove a 1995 Mercury Sable Wagon for several months and didn't have these complaints. The wagon had more glass area and a larger cabin volume compared to the MM to cool down.

Steve

Mine puts out high 30's from the vents, what I was trying to say is; if the design is flawed, is mine an aberration that works very well by mistake? My 95' CrownVic also works very, very well.

If there is a basic design flaw, then I have been very lucky twice.

GreekGod

08-20-2006, 04:32 PM

What about all the (30,000+?) New York city Panther chassis taxi-cabs? Do they have bad A/C systems? Methinks someone knows a simple solution to our problem. Does Ford have a "common problem" data base for technitions and zone reps to access? It seems there is no TSB on the Panther A/C system.

SergntMac

08-21-2006, 02:34 AM

My A/C is fine on both MMs, just bumping this to round out the "100 posts" thingy...

ShelbyMotorspts

08-21-2006, 10:10 AM

Mine puts out high 30's from the vents, what I was trying to say is; if the design is flawed, is mine an aberration that works very well by mistake? My 95' CrownVic also works very, very well.

If there is a basic design flaw, then I have been very lucky twice.

Smokie I see your point and even mentioned to the SVT dealer that other MM owners have told me that have gotten 37 degree vent temps from their car. Let's just say the dealer didn't believe it.

The only real comparison I can do now is with another MM right next to mine. Same car, same outside temp, same humidity level should result in a more accurate comparison.

Will post the results when I can find another MM owner here in SoCal.

Steve