2003 Grand Marquis A/C EATC Needs Replacement

[dabe]

I need to remove the EATC on my LSE to check for vacumn leaks and possible replacement. Self Test does not indicate any problems. However, A/C blows cold air from defroster and floor vent only. Can anyone guide me on removing the EATC module from the dash?

[sleepy hollow]

I have the same exact problem on my 2003.

Here is what I did (I am working from memory, so please be sure you verify what I suggest with your actual experience and what you see as you perform these steps):

Using a small slotted screwdriver with a rag over the end to avoid scratches, carefully pry up one side (left or right) of the wood trim piece that runs on the dashboard from the right side of the steering column to the passenger door.

When you can get a finger under and then your hand around the piece gently rock the piece in and out until it pops off working from one side to the other lengthwise. I usually start on the passenger side and work back to the steering column. When it comes free, you will have a long plastic piece including the trim "rectangle" where it goes around the climate control box.

Remove any electrical connectors from the back so you can set this piece aside. Some of the connectors are bit tricky so study them before disconnecting. They each have a trick to them and they are often different "tricks" from one to the next. Never yank on them. When you figure out the trick it will come pretty easily.

Next unscrew the 9/32 hex trim screws that are revealed and that surround the ATC box. Cannot recall exactly how many, but at least 4, maybe 8.

Once these trim screws are removed you should be able to slide the box out and look at the vacuum connectors on the back.

You should also be able to see the vacuum motors back against the firewall.

Make sure you have a bright light to see well.

Before disconnecting the box, start the engine (or you may be able to simply turn the ignition switch on without starting her up) and play with the settings. Watch the control motors. In my case the one on the right (passenger) side is the dash vent motor, the left one is the def/floor controller. Only the left motor would do anything. There is a little plunger on the end connected to a lever. When vacuum is applied to the motor it extends the arm and works the damper to direct the air.

If the left motor works, that indicates you have vacuum at the ATC box.

(If not, you probably need to troubleshoot the vacuum source. It starts in the engine compartment and travels through the firewall to the box.)

In my case, I did not do any of that since the left motor worked.

So, to test the right motor, I simply reached in, and switched the blue vaccuum line on the non-working motor with the yellow (I think) line from the working motor. In other words take the line off the right motor (dash vents) and replace it with the easiest to reach line on the left motor.

Now, when you select floor/def or one of the non-auto settings, you probably will get air from the dash vents. If not, then your motor may be bad. Though I doubt it.

So, that is how I left my car for the time being. I have the vacuum lines reversed. You have to run the fan manually, and set the selector to defrost/flr, but you get cool air where it does good.

Ok, so before I reassembled the dash, I also removed the box and disassembled it. There are 4 vacuum actuators inside the box. My bet is that the one connected to the blue line is bad. So, I am trying to find a used box to cannibalize. Have not had time to run that down, but in the meantime, the problem is solved and the A/C flows freely.

Hope this helps.

[FordGuy1]

Hi
Just an FYI,
I sent my ATC Climate Controller to A Company in Tennessee ,Auto & Truck Electronics,www.autoecu.com They advertise a rebuild for the ford ATC Climate Controllers on Ebay where I found them,they had a 2 day turn around and I received it back a few weeks ago and it has been working perfectly ever since.Installation was plug and play, Price wasnt bad either $179 compared to the $600 Dealer wants and they pay shipping..They also supplied me with removal Instructions. (My 2 cents )

[sleepy hollow]

Thanks for the post. That is very helpful.

So, let me also update my situation. I have been running with the vacuum connectors switched. That worked fine - for a while - enough to get through the summer. Then the same thing started to happen, that is, the air stopped blowing from the dash vents and reverted to the defroster and floor outlets.

Now I suspect a vacuum leak. I have looked at all the hoses I can find that connect to the little vacuum "manifold" on the firewall in the engine compartment. I seem to have vacuum at the black box on the driver's side on the fender in the engine compartment. Though not sure how to test this box and not sure if it comes apart. Cannot find anything to further troubleshoot.

So, I now have the luxury of time to properly diagnose and fix the system. Can someone tell me how I can troubleshoot the vacuum system to the EATC module? The EATC module has always self-tested ok with no codes. I hate to pay $200 just to find out the module is fine and there is a $5 problem somewhere else.

Thanks

[sleepy hollow]

Here is an update to my situation. Well I lived through the winter with just hot air from the defroster vents. Not a big deal, but as summer is approaching I was concerned to get the darn dash vents working again. After carefully inspecting tehhe vacuum system, I determined that I was satisfied there was plenty of vacuum to the head unit. So, I sent the head unit to the rebuilder in TN that Fordguy1 recommended.

Thanks, Fordguy1! Best $180 I ever spent. Sent the unit last Friday ($20 or so for 2-day fedex). Received it yesterday, and popped it back in. Viola! Works like a charm! Plus they offer a lifetime warranty, so this gives me great confidence that the next problem with the car will NOT be the EATC.

Problem solved and ol' cheapskate me is smug and satisfied.

[TheRealSystek]

Ok, I had been offered a company car for $750 cause the AC would not blow through the dash vents. Only through defroster and floor vents no matter how it was set. i did some research and found information on another site on what to look for and a place online that charges $180 to rebuild the EATC and fix this issue(ATE:High Quality Rebuilds at Exceptional Pricing). They also had a how to remove document although it was not accurate for my 1999 GM, it was helpful though...

I took the trim off the car that exposed the EATC module and I first checked the vacuum lines. Come to find out that one of the lines had been pinched between the lower chassis bar and dash support bar. The dash had been previously removed to replace the heater core. mechanic apparently didnt replace it properly and caused this problem.

company's loss, my gain. I took pix and will try to post later but since it was hard to find any information on this issue and possible fixes other than Ford's quote of $2k to fix it(that is what they quoted our shop), I thought I'd post this to document the issue and fix.

All this took me less than an hour to troubleshoot and replace all trim, radio and eatc!

[twnturbotim]

just to let you know,the EATC module is rebuildable but not for the faint at heart.each one of the 4 vac. selenoids have a tiny o-ring that i had to get(having a large selection already).once completely disassembled,the last thing will be removing the coils from the steel bypass tube,revieling the o-ring(that seals the tube at the plastic housing) just a little vacume leaking will cause problems. TurboTim

[everett67]

Originally Posted by twnturbotim

just to let you know,the EATC module is rebuildable but not for the faint at heart.each one of the 4 vac. selenoids have a tiny o-ring that i had to get(having a large selection already).once completely disassembled,the last thing will be removing the coils from the steel bypass tube,revieling the o-ring(that seals the tube at the plastic housing) just a little vacume leaking will cause problems. TurboTim

google ford eatc rebuild an step by step direction with pictures will guide you threw rebuild make sure you use the correct o ring 9/32 O.D. once unit is out the rebuild will take less than an hour. be sure to change all 4 o rings. cost to fix less than $1.. {important use correct o ring} a pack of 50 cost $1.67 from fastenal 9/32 O.D.