QuestionQUESTION: Yesterday, while driving down the road, the AC/heater blower stopped working and at the same time, the instrument panel consisting of the speedometer, tachometer, fuel gauge and temp gauge all stopped working also. The ATC digital temperature readout and the selector buttons all seem to be working and the electrical failure didn't affect the engine running so I was able to drive the car home without the instrument panel working nor the AC. I checked all the fuses on the left hand side of the dashboard and they are all good. Can you tell me what caused my electrical failure problem and how to fix it? Thanks
ANSWER: Hi Ed,
It appears to me that you may have lost power to the body computer as it is the center for all the digital signals for the dash readings and for the ATC digital controls to the blower via the blower module. The fuse #17 (5 amp) on the left side of the dash is the one I would look closely at (4th from the left, bottom row). If that looks good (no cracks in its wire) then check for voltage on the fuse when the ignition is in the run position. If you don't have voltage then the ignition switch section that powers only that fuse is not making good contact. You could spray some circuit cleaner inside the switch (after removing the tilt lever attaching screw and then the steering column lower cover, to get to it) as an attempt to repair the poor contact situation. But start with the fuse itself.
Roland
PS Use the "thank and rate" tab to get back with further question/progress, where there is a space for 'comments'.
---------- FOLLOW-UP ----------
QUESTION: I have another problem with the ac sytem sometimes blowing out hot air, like the heater is on, even when the digital temp reads 60 degrees and the selector buttons are set appropriately and the ac compressor is engaged. Sometimes it just starts by itself and when it is blowing out the hot air it cannot be stopped/shut-off unless you turn off the ignition switch. Any suggestions as to what may be causing that problem?
ANSWER: Hi Ed,
There is one possibility for the blower go on and not being able to shut off and that is that the blower power module is breaking down. That is located in the air duct near the blower motor. You would find it by following the blower moter wire to the plug where it is connected to that module. Remove the lower edge of the dash on the right side for better access. The situation might progress to the point where this is no longer intermittent and that would be a pretty good sign that the solid-state module that produces the 14 different voltage levels for the blower is what is wrong.
An alternative test should be done to see if the ATC computer has recognized any problems and described them in the form of two digit fault codes stored in its memory. You can do the readout yourself:
The unit does have a self-diagnostic capability. The engine has to be running and the car not in motion to do the test. Simultaneously press the floor, mix, and defrost buttons, (the 1st,2nd and 4th on the top row) and see if the display unit begins to blink. Release the buttons when it has started to do that and then after it blinks for a while longer watch for two digit numbers to appear on the readout. Those are the fault codes. If the first number appears and stays in place, push on the first button in the bottom row (panel) to continue the readout. At the end of the readout the unit will return to normal settings.
Then write back with the number(s) and also tell me more about exactly what is wrong with the function of the unit. The numbers range from 23-36.
Roland
PS Thanks for the kind evaluation and nomination
Roland, I performed the self diagnostic test of the ATC as you suggested and the codes shown were 23 and then 36. It did not return to its normal setting until I touched a button and when it returned to its normal setting it started to work perfectly again and blow out cold air. I am very grateful for having the opportunity to communicate with an individual of your caliber and with your expertise in regards to Chryslers and can't thank you enough for your help. I hope others have been as fortunate. Thanks again
Hi Ed,
Thanks again for the rating.
The 23 code means that there was a problem with the feedback loop from the blend air door (which controls the mixture of cold and heated air to produce selected temperature) to the ATC. (I suspect this "loop" is to verify that when the computer asks for that door to be moved that it reports back the physical result of that command). That is carried on a red/white wire from the mode door plug to pin 5 of the black plug of the body computer. It is consistent with your observation of a loss of control of the temp of the air that you described. It is probably an issue with the blend door actuator (which moves the door in response to commands from the ATC) or the door motion detector or that wire. I don't have a detailed troubleshoot on the ATC but that actuator is removable and I believe is on the bottom of the housing (though I can't be certain based upon what the manual shows (or doesn't show)). The 36 says there is/was a problem with the ATC head unit communication which too is consistent with the fuse failure and resultant power supply problem to the ATC that you experienced.
So I am disappointed that we don't know any more than we already did except to focus toward the blend door actuator/feedback if the problem continues. I believe you can erase these codes by disconnecting the battery for 10 minutes if you choose to do that at this time.
Roland
---------- FOLLOW-UP ----------
QUESTION: I have another problem with the radio/dvd in that it works sporadically. One day it will play/work and then it won't for several days. There is power to the unit at all times because the clock and digital station numbers always work. When the radio/dvd is turned on and it doesn't work/play there is a deep humming annoying bass sound coming from the speakers. Is this unit computer controlled? Do you think the radio/dvd player can be fixed or does it need to be replaced?
AnswerHi Ed,
Is this a deluxe unit ("Infinity") or a base/moderate init? The wiring is a bit different so it would help to know that. I assume it is a factory installed unit. The computer is not involved, but there are some electrical component that can introduce hum.
Roland
