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kirk
08-17-2018, 08:44 AM
So the last time I took my car out I tried to use my AC and the air comes out at the floor, no matter what I do with the controls. Checked for EATC codes and got none.

Safe to assume this is a bad damper actuator? Is it the one behind the radio?
RF Overlord
08-17-2018, 09:07 AM
May still be an EATC head unit issue.

The default setting for a loss of vacuum supply is to go to defrost. Defrost and floor share a common actuator, so there has to be vacuum pulling it to the floor position. If you put the EATC into Vent and it does not open the vent door, then it sounds like the issue may be internal to the head unit.
kirk
08-17-2018, 09:58 AM
May still be an EATC head unit issue.

The default setting for a loss of vacuum supply is to go to defrost. Defrost and floor share a common actuator, so there has to be vacuum pulling it to the floor position. If you put the EATC into Vent and it does not open the vent door, then it sounds like the issue may be internal to the head unit.

I assume then that there is an air switch that puts vacuum to the actuator based on a command from the controller that could also be the issue?

I'm slow today. Just occurred to me that if the switch is bad I would have air to the defrost.
fastblackmerc
08-17-2018, 11:09 AM
https://www.mercurymarauder.net/forums/showthread.php?t=99619
kirk
08-17-2018, 12:37 PM
https://www.mercurymarauder.net/forums/showthread.php?t=99619

Looked there before I posted. My issue isn't one of the 4, but thanks for trying.
Turbov6Bryan
08-17-2018, 08:20 PM
I would check the vacuum to the head unit, start the car and pull the hose assy off the back of the eatc.

That white hose might be ripped, or there is a also a quick connect that looks like the connection at the back of the eatc on the pass side under dash.

Idk. I'm just trying to help
RF Overlord
08-18-2018, 10:49 AM
The black hose is the vacuum supply. White is for fresh/recirc, blue is for the panel vents, and red and yellow are for the floor/defrost dual actuator.


I assume then that there is an air switch that puts vacuum to the actuator based on a command from the controller that could also be the issue?The vacuum "switch" is the plastic manifold that the solenoids attach to. When the controller commands a particular solenoid to open, it provides vacuum to the appropriate actuator.
kirk
08-18-2018, 12:45 PM
Further investigation leads me to believe it is the solenoid O-rings. While air is coming out on the floor, it is also coming out the defrost. I was also getting heat today that I wasn't feeling the other day. Age and symptoms indicate it's worth changing the O-rings. Probably won't happen for a month or two.

Thanks for all the input.
RF Overlord
08-18-2018, 01:37 PM
Remember to use silicone o-rings, size -007. Also check the manifold for cracks or porosity. JB Weld is your friend if you find any.
kirk
08-18-2018, 04:36 PM
Remember to use silicone o-rings, size -007. Also check the manifold for cracks or porosity. JB Weld is your friend if you find any.

Big help there. Thanks
fastblackmerc
08-18-2018, 08:18 PM
I can repair your EATC and replace the bulbs with LEDs.
kirk
08-19-2018, 05:40 PM
I can repair your EATC and replace the bulbs with LEDs.

Thanks, I'll ponder that.
12odee
09-19-2018, 12:45 PM
How did it go? Did you get it fixed?
Zack
09-19-2018, 01:10 PM
I had a very similar problem. The blend door is made of plastic with a plastic hinge. The hinge broke from normal use. Took me an entire day to fix, with hardware store bought hinges and ingenuity
kirk
10-25-2018, 02:50 PM
So I finally got to this today and I already have to stop and ask a question.

The instructions state "But first, make sure they hold vacuum when not energized. Connect a hose to the center vacuum port (where the black tube was connected) and suck it. It should hold vacuum. If it doesn't, the following fix probably isn't for you."

I have my EATC out and I did a vacuum check on the center port and it leaks.

I thought the whole issue here is that the O rings leak and it won't hold vacuum. Is there some other seat or seal in the solenoid that should hold this or are the instructions backwards?
fastblackmerc
10-26-2018, 05:11 AM
So I finally got to this today and I already have to stop and ask a question.

The instructions state "But first, make sure they hold vacuum when not energized. Connect a hose to the center vacuum port (where the black tube was connected) and suck it. It should hold vacuum. If it doesn't, the following fix probably isn't for you."

I have my EATC out and I did a vacuum check on the center port and it leaks.

I thought the whole issue here is that the O rings leak and it won't hold vacuum. Is there some other seat or seal in the solenoid that should hold this or are the instructions backwards?
The EATC o-rings need to be replaced.
kirk
10-26-2018, 05:55 AM
The EATC o-rings need to be replaced.

Thanks. That's what I thought and I'm moving in that direction. I was just thrown off by that sentence.
Invective
10-26-2018, 06:02 AM
So I finally got to this today and I already have to stop and ask a question.




Hoping everyone is using a Mityvac or something similar. On my 2nd; haven't used it in years. Wore out my first one diagnosing electro-thermo-vacuum devices from yesteryear.


https://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e 95/i/m/image_17337.jpg
RF Overlord
10-26-2018, 08:56 AM
Sounds like the instructions are poorly written. The black tube (vacuum source) goes to a manifold that all the solenoids connect to. If you can hold a vacuum on the black tube, then you do not have a solenoid o-ring leak.
fastblackmerc
10-26-2018, 10:44 AM
Sooner or later ALL EATC solenoids WILL leak.

BTW... Of all the EATC's I've repaired I had only 1 that the manifold was cracked.
NorthShoreChiMM
10-26-2018, 03:15 PM
Highly recommend FBM work. Just did mine a few weeks ago, O rings and led lights for just 45 bucks and shipping. It looks great, I didn't even know the blower speed adjuster was supposed to light up.
kirk
10-26-2018, 04:20 PM
Well I got them changed with silicone 007 O-rings.....

and it still leaks, though not nearly as bad as it did. No signs of cracks.

The good news is the guy at the supply house said it wasn't worth the paperwork for 4 O-rings and gave them to me for free.

Back to the drawing board.
Marauderjack
10-27-2018, 06:37 AM
Send to FBM......problem SOLVED!!:beer::bows:
kirk
10-27-2018, 03:57 PM
Now that I've looked at this in more detail I understand these instructions. I also find them a little misleading and technically incorrect.


So I finally got to this today and I already have to stop and ask a question.

The instructions state "But first, make sure they hold vacuum when not energized. Connect a hose to the center vacuum port (where the black tube was connected) and suck it. It should hold vacuum. If it doesn't, the following fix probably isn't for you."

I have my EATC out and I did a vacuum check on the center port and it leaks.

I thought the whole issue here is that the O rings leak and it won't hold vacuum. Is there some other seat or seal in the solenoid that should hold this or are the instructions backwards?

The O-rings do not seal the vacuum under no-load situations. They're only required when the solenoid is energized. And I'm sure they were the cause of the problem.

It's the seal on the solenoid plunger that seals while de-energized. I'm not too worried about that leak because it's leaking to the vent, and the plunger will be harder to find than an O-ring.

So it goes back together.