Hopefully someone will have an answer. 1998 X EB with the 4.0 SOHV engine. I want to do the blend door repair posted at the top of the forum but I can't get the actuator to work. Tried a new one at the dealer and it doesn't work either. An independent repair shop I trust says to replace the A/C-Heater Control Head @ $463.57 just for the part, but they're not positive that's the problem. Anybody have any experience with this or other suggestions of things to try?

TIA,
Rick

 

Does it have power going to it? Blown fuse? Bad switch? Unplugged at the switch? Are you sure the blend door is broken?

 

HomerWinzlow,
Thanks for replying! I've checked all the fuses at the panel and they're all good. The 6 pin connector is tight, but I haven't traced it back to its origin. By "bad switch" do you mean the push buttons on the AC/Heater unit? If so, I've haven't checked them and don't really know how to.

The reason for doing this is because my AC only works on Max AC, and only as long as the car is not moving. As soon as I start driving the air coming from the vents is no longer cold. The heater doesn't work either. Also with the actuator removed I can see with a mirror that the blend door connection to the actuator is broken. Any help will be appreciated very much.

 

Well it appears you have EATC rather than manual AC. You already know you will have to repair the plenum so your next step is to isolate the controller problem. First try the self test.... Do this test with the new blend door controller installed. It may just start working after the self test is complete.

Electronic Automatic Temperature Control Module Self-Test

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 (DTC) 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 performing 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 self-test and clear all diagnostic trouble codes, 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.

 

I have tried to do the self-test with the old actuator in place and nothing happens. I did it several times following the instructions and nada. The engine was running when I did the test.
The dealer let me try the new actuator at his facility, and when it didn't work he agreed to take it back. I will go back to my dealer, buy a new actuator, try the self-test again, and let you know what happens. Thanks again for your help.

 

Ok, sometimes with the old actuator it will lock up the firmware in the control head, so after installing the new actuator you have to reinitialize the control head. Sometimes this can be done by a self test with the new controller in place or sometimes with an NGS scan tool to clear the code.