Hvac "gurus"......help!!!!

[Marauderjack]

Well,

The weather has been so mild lately that I have left the HVAC on "Vent" since Sunday......I noticed yesterday AM that the fan was not running very fast and using the steering wheel fan control attempted to speed it up.....Nope??:confused: I was busy and forgot about it until today when it was raining and muggy.....turned HVAC to "Auto" and nothing.....No fan at all it seems??:argue:

Drove down the road as I was going to a meeting and cool air was coming out the vents but only while running and varied with speed....."Ram Air"???:cool: BTW.....the compressor runs OK!!:rolleyes:

I ran the diagnostics on the HVAC controller (replaced under warranty last Sept.) and it checks OK.....checked all fuses and A-OK......unplugged the fan motor and had only 0.89 volts at the plug and the fan was clearly NOT running!!:mad2: I connected a 12V lawnmower battery to the unplugged fan and it roared to life....so the fan motor seems to be OK!!:beer:

Called my dealership service mgr. and he said the HVAC controller may self test OK but could be bad but he suspected the blower motor "resistor"....$80.00 controller for the fan speed?? Where the heck is this thing and what does it actually do??:confused:

Ideas anyone?? This one is on my "dime"......warranty over last November!!:bigcry:

Thanks!!

Marauderjack

[rvaldez1]

Fan motor relay went south??

[Marauderjack]

OK.....Where is the relay??:confused:

[rvaldez1]

In the power distribution box, check the fuse and relay for the blower. Even if the fuse looks good, check it or use a different one. The cheapest thing would be electrical i.e. the fuse or relay. Other than that, the speed controller is somewhere near the passenger side firewall and is a somewhat common problem.

[Marauderjack]

In the power distribution box, check the fuse and relay for the blower. Even if the fuse looks good, check it or use a different one. The cheapest thing would be electrical i.e. the fuse or relay. Other than that, the speed controller is somewhere near the passenger side firewall and is a somewhat common problem.

Fuses are OK....

I think it is the fan controller!! It may actually be behind the glove box inside the car since I see nothing in the engine compartment but the wiring harness and the plug to the fan motor!!:cool: What's this thing look like??:confused:

The dealer should have it tomorrow PM??:beer:

Marauderjack:burnout:

[Dennis Reinhart]

The fan is also controlled by the AC pressure switch just in front of the SC fan speed is determined by AC head pressure, the fan has to come on with the AC or you will fry the compressor or blow a AC line.

[KilledKenny]

Ok, at the Blower Motor connector there are 2 wires. 1 Pink/White and the other is Orange/Red. Ford uses a ground side switching to control blower speed so when the key is in the on position you should have battery voltage at the Pink/White. If not you either have 1 of 3 problems, Blown 40 amp fuse F1.103 in the underhood fuse box, a faulty blower relay (also located in the underhood fuse box) Or a wirring concern in that circuit. Here is a wirring diagram and location chart for ya. Hope this helps.

[rvaldez1]

My thing is, the fuse might look ok, and even pass a multimeter test, but if it is a partial break it will pass the 3v at nothing amps. give the relay a few good knocks as it may be seized.


Fuses are OK....

I think it is the fan controller!! It may actually be behind the glove box inside the car since I see nothing in the engine compartment but the wiring harness and the plug to the fan motor!!:cool: What's this thing look like??:confused:

The dealer should have it tomorrow PM??:beer:



Marauderjack:burnout:

Good, great diagrams, all you can do is troubleshoot now.

Ok, at the Blower Motor connector there are 2 wires. 1 Pink/White and the other is Orange/Red. Ford uses a ground side switching to control blower speed so when the key is in the on position you should have battery voltage at the Pink/White. If not you either have 1 of 3 problems, Blown 40 amp fuse F1.103 in the underhood fuse box, a faulty blower relay (also located in the underhood fuse box) Or a wirring concern in that circuit. Here is a wirring diagram and location chart for ya. Hope this helps.

[Marauderjack]

Ok, at the Blower Motor connector there are 2 wires. 1 Pink/White and the other is Orange/Red. Ford uses a ground side switching to control blower speed so when the key is in the on position you should have battery voltage at the Pink/White. If not you either have 1 of 3 problems, Blown 40 amp fuse F1.103 in the underhood fuse box, a faulty blower relay (also located in the underhood fuse box) Or a wirring concern in that circuit. Here is a wirring diagram and location chart for ya. Hope this helps.

KilledKenny.....

Pink/White has battery voltage......I switched the relays from fan to rear defogger and no change?? 40 Amp fuse seems OK....switched two of them and no change!!:mad2:

What and where is the fan "Resistor" the dealer told me about?? It is $80.00 according to them and apparently is the fan controller??:confused:

Thanks for your help!!

Marauderjack:argue:

[KilledKenny]

The blower speed controller is located in the engine compartment on the passanger side in the heater case. Here is the info on how to remove it. Its a bastage to change and make sure the vehicle is cold. :cool:

[JMan]

Kenny, you da man! Good job and thanks for the diagrams. You're on it Jack, those resistors do fail. It's kind of a pain on the Marauder with those ginormous heads. Do as Kenny said, dead cold only. It only has two fasteners if I'm not mistaken and is located on the evaporator case behind the Pass' side head (Bank1).

Good luck,

J

[Marauderjack]

Holy Moly......

Ya have to drain coolant to install the blower control?? Who the heck designed this and why this way??:confused:

Guess I'll have to assume the part is bad.....bring it home to install (cold)....and hope for the best??:argue:

Kenny.....Thanks for all your help.....I'll find out later today what it is.....I hope??!!:mad:

Marauderjack:cool:

[Marauderjack]

The blower speed controller is located in the engine compartment on the passanger side in the heater case. Here is the info on how to remove it. Its a bastage to change and make sure the vehicle is cold. :cool:

Kenny.....

Is the blower speed control actually tied into the cooling system or do you just remove the heater hoses to get to it?? I'll have to get some more of that yella anti-freeze while I'm at the dealer today!!:rolleyes:

If where it is happens to just be a place for it to live.....they sure picked a bad spot!!!!!!!:shake:

Marauderjack:help:

[JMan]

Holy Moly......

Ya have to drain coolant to install the blower control?? Who the heck designed this and why this way??:confused:
Kenny.....Thanks for all your help.....I'll find out later today what it is.....I hope??!!:mad:

Marauderjack:cool:

I'll jump in. If you clamp the heater hoses, e.g. with vice grips, there will be very little loss. Don't drain it.




Kenny.....

Is the blower speed control actually tied into the cooling system or do you just remove the heater hoses to get to it?? I'll have to get some more of that yella anti-freeze while I'm at the dealer today!!:rolleyes:
Marauderjack:help:

With the SOHC engines, there's much greater clearance. The resistor is located in the HVAC plenum for (air) cooling and is not tied to the cooling system at all. You're removing the heater hoses to gain access to it. You may be able to do it without removing them, but it's gonna be tough on a Marauder - It's those damned monster heads, again!

Best,

J

[Marauderjack]

Thanks J.........

I just went and looked again and one hose goes right across the speed controller...looks real tight!!:argue: I guess ya have to live with some of these inconveniences with a "Parts Bin" car!!!:beer:

I suppose the speed controller is also temp controlled since it is tied into the plenum??:confused:

I wonder if I can simply get the plug off.....plug the new one in and see if it works before going through the entire installation?? If it doesn't work then I suspect it is the HVAC unit AGAIN!!!!:mad2:

Marauderjack:rolleyes:

[Marauderjack]

I just tried to loosen the filler plug on the coolant crossover!!!!!!:argue: :argue: :mad2: :mad2:

Why is this damn thing so hard to unscrew??:eek: It took a 1/4" BREAKER BAR and I bashed my thumb in the process!!!!:mad2: :mad2:

But.......I got 'er loose!!:beer::D

Marauderjack:shake:

[Seneca]

Hey Jack. I had the same issues with my mm a few months ago. I did end up replacing the resistor.i think it was two sheet metal type screws. I didnt drain the coolant on mine but it was tight getting it around the heater core hose. also the resisitor for my car (2004) was about 40 bucks from a dealer close by.
Good luck let us know how it goes. Seneca

[JMan]

MJ,
The resistor is used for all blower speeds and get very hot due to the electrical resistance and its coresponding heat build up. They place it there to keep it cool with air blowing over it and to keep stuff from hitting it and causing smoke or potentially fire (It gets pretty hot!). You can just plug in the new one for test purposes. If you have full blower control again you're in. Don't leave it like that though, mount it properly! You may not have to bleed your cooling system if you clamp the hoses. Just top it up in a few days and keep an eye on it.

Damned parts-bin cars!!! :D

J

[Marauderjack]

Seneca,

Did your fan just quit blowing completely??:confused:

It looks like I can get it without removing the heater hoses??:cool:

Marauderjack:shake:

[Marauderjack]

Ahem.....

Why didn't someone tell me how big this sucker is.....SEE PHOTO!!:eek:

I got it out without taking the hoses off.....Putting it back may be another story though!!:mad2:

And YES.....It must get pretty HOT with that much heat sink inside the plenum!!:rolleyes:

Stay Tuned!!:confused:

Marauderjack:D:rolleyes:

[Marauderjack]

TADA!!!!!!:beer: :beer:

I am COOOOOOL now.......AND I didn't have to disconnect the heater hoses!!!:banana2:

One of the techs at the dealership said sometimes you can smack the controller and it will work....in one case for over a year now??:eek:

I think the new one will be just fine!!!;)

Thanks for all the help folks!!:bows:

Marauderjack :snowman:

[teamrope]

Perfect timing... The wifes gave out Friday. Do you have a part #?

[Marauderjack]

6W7Z-19E624-A

Good Luck!!:beer:

Marauderjack:burnout:

[teamrope]

Thanks Jack! :beer:

[Seneca]

Yay!.. Way to go Jack glad you got your problem taken care of. yes My heater did go all the way and the resisitor worked for me. Take care. Seneca