Problem EATC Heat Coming Thru Vents

[04MRADR]

I have a 2004 Marauder and today I noticed my heat comes thru the vents when I choose either the floor, defrost, or floor and defrost buttons instead of coming through the floor or dash like it should. A few years ago I had a problem where my air conditioning came out of the floor and dash and nothing came out of the vents. I recall someone suggested I replace the washers in the EATC and sure enough that fixed the problem. I was wondering could this be the same thing again since I read elsewhere in another forum that the washers tend to dry out over time and not seal properly. Also noticed when I turn on or off the engine it sounds like a door opening or trying to open or close under the dash on the passenger side. Don't know if that has anything to do with this problem. Any suggestions on what the problem may be and if the washers I think last time a club member said you get them from a supplier in New Jersey. If someone could provide me with where I get the washers that would be most appreciated. Thanks ever so much. Have 219 K on the Marauder and still drive it and love it. Thanks for your help in advance. :)

[Ambitious1]

You may want to reach out the FastBlackMerc, he is an expert in all thing involving the HVAC system.

[NorthShoreChiMM]

FBM has an excellent repair thread with all diagnostic and repair steps. Its a sticky I believe

[RF Overlord]

Washers? If you meant the o-rings, as long as you used silicone ones they should not need replacement again.

The "door closing" sound on start-up or shut-down is normal.

Having air coming from the vents all the time means either the vent door actuator is bad or the vent door itself is disconnected or broken...not an uncommon issue.

[Svashtar]

This happened to me two years ago, after some auto body hacks in town beat on the car for a week fixing the right front quarter panel. I was able to fix it by resetting the EATC with the self test. The system ran through its cycle, there was a lot of thumping under the dash which I took to be the blend door opening and closing, then everything started blowing normally.

Try this first anyway:

“Key on, engine running: Press OFF and FLOOR simultaneously, then press AUTOMATIC within 2 seconds. The EATC will have to run some tests and do some thinking. It may take up to 30 seconds. Soon it may display some codes. Write these down. To exit self test press DEF.”

Look for error code 024 which is a fault in blend door calibration during the test, or code 025 which is an intermittent fault in blend door calibration. There are a bunch of others from 030 up to 125, but I don’t have all their descriptions.

Hopefully this will reset it for you like it did mine, but if not at least you gave it a shot and might get more info.


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[fastblackmerc]

This happened to me two years ago, after some auto body hacks in town beat on the car for a week fixing the right front quarter panel. I was able to fix it by resetting the EATC with the self test. The system ran through its cycle, there was a lot of thumping under the dash which I took to be the blend door opening and closing, then everything started blowing normally.

Try this first anyway:

“Key on, engine running: Press OFF and FLOOR simultaneously, then press AUTOMATIC within 2 seconds. The EATC will have to run some tests and do some thinking. It may take up to 30 seconds. Soon it may display some codes. Write these down. To exit self test press DEF.”

Look for error code 024 which is a fault in blend foot calibration during the test, or code 025 which is an intermittent fault in blend door calibration. There are a bunch of others from 030 up to 125, but I don’t have all their descriptions.

Hopefully this will reset it for you like it did mine, but if not at least you gave it a shot and might get more info.


Sent from my iPhone using Tapatalk

Here is the exact procedure:

Electronic Automatic Temperature Control Module Self-Test Procedure

Interior of the vehicle must be between 40 - 90 degrees while running the test. If not you may get false in-car temperature sensor errors.
•The EATC module self-test will not detect concerns associated with data link messages like engine coolant temperature or vehicle speed signals. A NGS tester must be used to retrieve these concerns.
• The EATC module self-test will detect concerns in the system control functions and will display hard diagnostic trouble codes (DTCs) in addition to intermittent diagnostic trouble codes for concerns that occur during system operation. The vehicle interior temperature should be between 4°-32°C (40-90°F) when carrying out the self-test. If the temperatures are not within the specified ranges, false in-car temperature sensor DTCs will be displayed.
• The self-test can be initiated at any time. Normal operation of the system stops when the self-test is activated.
• To enter the self-test, press the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The display will show a pulse tracer going around the center of the display window. The test may run as long as 30 seconds. Record all DTCs displayed.
• If any DTCs appear during the self-test, follow the diagnostics procedure given under ACTION for each DTC given.
• If a condition exists but no DTCs appear during the self-test, refer to the Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Improper Operation.
• To exit self-test and retain all intermittent DTCs, push the blue (cooler) button. The control will exit self-test, retain all intermittent diagnostic trouble codes and then turn OFF (display blank).
• To exit the self-test and clear all DTCs, press the DEFROST button. The vacuum fluorescent display window will show 888 and all function symbols for one second. Then, the EATC control assembly will turn OFF (display blank) and all DTCs will be cleared.
• Always exit the self-test before powering the system down (system turned OFF).
• Intermittent DTCs will be deleted after 80 ignition switch ON cycles after the intermittent condition occurs.

[Turbov6Bryan]

^^^ that should be a sticky

Do we have a section here, most common issues and how to test and repair?

That would be awesome

[Zack]

I just had the identical problem you are having OP. The diverter door itself had self destructed and was just laying there. It required the complete removal of the dashboard, and a very difficult home repair. If I had to do it again, I would have bought a new HVAC box. Good luck

[Zack]

The diverter door hinge is made of plastic, just like you'd find on a beer cooler.
After so many cycles, they fail. Absolutely stupid design.

[fastblackmerc]

^^^ that should be a sticky

Do we have a section here, most common issues and how to test and repair?

That would be awesome

It is!

Interior Electrical/Electronic forum

[fastblackmerc]

The diverter door hinge is made of plastic, just like you'd find on a beer cooler.
After so many cycles, they fail. Absolutely stupid design.

Had the broken blend door on my '98 Ranger. Bought a kit to replace it that required you cut the bottom of the HVAC case. I replaced the blend door actuator while I was in there.

[Zack]

Had the broken blend door on my '98 Ranger. Bought a kit to replace it that required you cut the bottom of the HVAC case. I replaced the blend door actuator while I was in there.

But in my case, it was not the blend door. It was the door that decided vent or floor.

[b1vjgb3]

Does anybody know where the heater control valve is located ?

[b1vjgb3]

The problem with my silver car is that the heat doesn't come on right away. I can get heat by turning the EATC up to 90 and revving the engine to about 3000 rpm and then the heat comes on.

I suspect the problem to be either the heater control valve (don't know where it is but I have a new one) or the heater core is clogged.

The car has just over 198,000 miles on it.

[fastblackmerc]

Ford and other manufactures eliminated the hot water valve and replaced it with the blend door. Apparently the continuous flow of water thru the heater core is better than no flow.

[fastblackmerc]

The problem with my silver car is that the heat doesn't come on right away. I can get heat by turning the EATC up to 90 and revving the engine to about 3000 rpm and then the heat comes on.

I suspect the problem to be either the heater control valve (don't know where it is but I have a new one) or the heater core is clogged.

The car has just over 198,000 miles on it.

You might have a sticking / stuck thermostat or air in the system.

[RF Overlord]

If revving the engine causes the heat to come up, you have an air bubble in the system. It's very common. There are numerous threads here detailing how to burp the system. If the heater core was clogged, you'd nave no (or reduced) heat all the time.

As fastblackmerc said, there is no heater control valve.