FOUR MOST COMMON MARAUDER HVAC PROBLEMS

fastblackmerc said:
FOUR MOST COMMON MARAUDER HVAC PROBLEMS​

PROBLEM: Air blows out of the defrost vents instead of where it should.
Most likely the o-rings on the solenoids, inside the Electronic Automatic Temperature Control (EATC), need to be replaced. The cheap rubber hardens over time causing a vacuum leak. I’ve replaced some that are so brittle that they break into pieces when I remove them. You will probably see that all four o-rings are square, square doesn’t seal a round cylinder very good. They should be replaced with high quality silicone o-rings and a small amount of silicone dielectric grease. If you buy another EATC, even a new one, you will eventually need to replace the o-rings.

Could also be a vacuum leak inside the car or under the hooD
Could also be the electronics inside the EATC.

NOTE: If you disconnect the vacuum connector from the EATC you might notice that there is one hose “missing”. It’s not supposed to be there. Looking at the nipples on the back of the EATC one has no opening.

PROBLEM: Blower doesn’t work or only blows at one speed.
Most likely it is the Blower Control Module (BCM). Tap the BCM (under the hood, behind the passenger side cam cover). If tapping the BCM makes the blower work correctly, the BCM needs to be replaced. Buying a new BCM (only buy a new one from FORD – aftermarket ones have a poor track record) will fix the problem but it will probably happen again due to the type of solder used. If tapping the BCM doesn’t make the blower come on then you probably need a new blower motor or the fan control / electronics inside the EATC can be bad.

PROBLEM: Temperature doesn’t regulate, its either too hot or too cold and or knocking noise coming from center of the dash.
Run the EATC self test, if you get an 025 or 025 code the Blend Door Actuator is bad.
The BDA moves a door that closes off either the heater core or the evaporator, providing just the right mix of hot or cold air depending on the temperature setting in the EATC. When the BDA goes bad it doesn’t move at all or it rapidly moves back and forth creating a knocking noise. The only fix is to replace the BDA. The part is less than $100.00 and again only buy a FORD one! Don’t buy an aftermarket as you don’t want to do the job again or pay the labor to get it done again as the dash need to come apart.

PROBLEM: No A/C
The A/C system is a closed system. If it is blowing warm or hot air, most likely there is something wrong with the A/C system. If you have to add freon to get the system to work, you have a leak in the system and unless you are experienced and licensed to work on the A/C systems (in most states) you need to take it to a professional. One of the most common problems is the bottom of the receiver / dryer rusts out due to its construction and location. If it needs to be replaced insist on an aluminum replacement part.
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Did you mean to say code 025 twice?

if you get an 025 or 025 code the Blend Door Actuator is bad.
 
Great thread, I was just pondering such questions.

My 04 Marauder has an odd Blower motor problem. I had experienced blower control module (BCM) failure on my old 94 and 96 Town cars, in that case there was no fan unless you manually selected full speed on the EATC. But with the Marauder it starts out fine, but then the fan ends up at full speed and one can't override it except for shutting off the Climate control. It does seem to be sensing the proper temp etc, as it will pulse back and forth a few times, and will start out at a proper speed.

In the old Town cars I was able to fix the BCM by soldering the main transistor connections on the circuit board

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Does this trick work with the newer style BCM with the much larger heat sink?

Secondly has anyone tried to interchange a EATC from another panther?

Both my 04's had the Oring failure, and the 04 LX was pre-failed when I bought it. The MM failed and the LX was temporarily out of service so I swapped in the LX EATC, but it did not work right. A few functions did not work, put it back in the LX and it worked fine. So I used the spare Orings and fixed the MM EATC and all was fine, of course it took much less time to do the job the second time.
 

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Whats the problem when you select vents or floor or which ever and the heat comes out from all of it and not the selected one?
 
We've had to change the accumulator on two 04's, bottom rusted. Easy to change, luckily my brother-in-law has the equipment to recharge AC.
 
And I have been flamed on about this in the past, and may get flamed again now. Just tested EATC got 888 code (everything ok). Had no air at all. Changed BCM, had AC for 3 min. Changed $14.00 relay... AC fixed.

I am a big believer in changing out 15 year old Relays first (I was out and ordered more on line.). On items like brake safety start (lock out) or AC, things that get used a lot, changing out Relays to new ones only makes sense! And saves dollars and time.
 
1Marauder said:
And I have been flamed on about this in the past, and may get flamed again now. Just tested EATC got 888 code (everything ok). Had no air at all. Changed BCM, had AC for 3 min. Changed $14.00 relay... AC fixed.

I am a big believer in changing out 15 year old Relays first (I was out and ordered more on line.). On items like brake safety start (lock out) or AC, things that get used a lot, changing out Relays to new ones only makes sense! And saves dollars and time.
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No flaming that, it's common sense. Especially how cheap & weak modern car relays are. 1st time I had a problem with a relay, I replaced all. Cheap prevention of being stranded somewhere. This has the added side benefit of having a fistful of known good relays for future troubleshooting and a spare in the glovebox.
 
EATC Issues....

Hello, I have a 2004 Mercury Marauder which I bought new. Paul Casey, RIP, talked me into buying it back when life was good. After driving his, like I stole it, I was sold. I bought mine over the phone, sight unseen. I'm in north Alabama.

I am another on the list for EATC/air conditioning issues. Four years ago I did the O-ring fix and all was wonderful again after that...now I am bewildered...I have done the O-ring fix again...as the air was blowing out the defrost and the floor. However, that did not fix my problem. I ran the self diagnostics and had no fault codes.

I checked the system for vacuum leaks, there are none. I have 20 inches of vacuum at the EATC.

I am confused and confounded. I can operate the electronics, such as the AC compressor, the blend door (Changing from hot to cold or cold to hot, the air is cold. The heat is hot.), the fan speed, via the EATC and MANUALLY jump the vacuum hose to operate the different vacuum actuators and they all work fine when I do this MANUALLY. I can make the AC blow out the DASH vents MANUALLY like they should do AUTOMATICALLY.

I have now replaced the complete EATC TWICE, did not phase the problem of making the air blow out the dash vents (Which it still doesn't) ... still blowing out the defrost and floor. I have replace the blower motor controller out under the hood mounted in the blower box ... just because I could...and then replaced that part again...because the first replacement made the blower quit working. I have taken the airbag out of the dash to check the blend door...it works fine...smooth and quiet...not gonna go there since I don't have to... After taking out the air bag and vent to the passenger far side, the EATC gave me a fault code of 025 and 052. I did not get any codes till I took out the air bag and vent... I figured I upset the system with the effort it took to get the vent plastic extension out, which was a lot. I reran the EATC self diagnostics and cleared the codes. Blend door still works smoothly and quietly. Codes did not, have not reappeared. I took out the inside temperature sensor and disconnected the large white hose and blew it out...to clear any possible obstructions in the ac blower box. I reinstalled the temp sensor, still no cure. I took the apron which covers the windshield wiper mechanism and cleaned out all the leaves and silt, because I could...made no difference. Cleaned out the blower box from the access on the firewall too. Made no difference.

What am I missing? Anyone got the solution? Any more parts I can replace?
 
EATC Issues....

Got it fixed today...replaced the vacuum solenoids in the second EATC and life is good again. I don't know how that did it...but it did.

After the fix I amazed myself by how quick the dash all went together...sure seams like it took days to get it apart. Anyway, Life is good again.

Thanks to all who offered information.
 
Rich Money said:
Got it fixed today...replaced the vacuum solenoids in the second EATC and life is good again. I don't know how that did it...but it did.

After the fix I amazed myself by how quick the dash all went together...sure seams like it took days to get it apart. Anyway, Life is good again.

Thanks to all who offered information.
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Take the "bad" solenoids apart and see what you messed up.

I'm guessing a torn o-ring or piston installed upside down.
 
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What if you start your car to warm it up in the morning and the eat is set to auto but when you cine back out 20 minutes later it's stone cold in your car and the climate control had done nothing. Seems there has to be an AAT sensor inside the eatc to determine the temp inside and too tell it what to do. Maybe it's bad? Anyone experienced this?
 
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