QuestionQUESTION: My problem seems to be different than what I've seen. I have a 94 Chrysler NY with ATC. No matter what I put the temp on I always get heat..no cool air..and only out of the defrosters. Any ideas?
ANSWER: Hi Linda,
There are electric motors in the distribution system that power the air distribution door and the door that controls the temperature by mixing warm and cold air to get the desired temperature. I suspect that both of those motors may not be working or that the power for those door motors is absent. Here is a copy or a response I sent to another owner of the similar vehicle to yours who was having an ATC problem that told him how to get a self-diagnostic readout for faults that the ATC may have recognized.
"a test should be done to see if the computer has recognized any problems and described them in the form of two digit fault codes stored in its memory. Did someone do such a inquiry? If so, what numbers did they get? If not 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.*
If the head unit doesn't respond at all, then check fuse #6 under the dash. There is also a 12V supply line to the control that is directly connected to the battery on a black/pink wire on the green plug on the rear of the control unit that should be checked to verify that you are getting that power to the control unit.
I would do a thorough readout before buying a new control unit. It may be a part in the air distribution system itself rather than the computer that is the problem. And you also might find a working used unit at a wrecking yard.
Roland
*The code numbers range from 23-36. You can also get a decoder list at www.allpar.com/fix/codes_climate.html "
So try those items and let me know the results.
Roland
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QUESTION: Hi Roland,
I did what you indicated and I got the flashing,,but no error codes. Surprisenly enough...now all my vents work and I now get cooler air instead of all hot!!
Thank you so much for your help..I have other situations I need info on..so I will be posting again!!
ANSWER: Hi Linda,
Thanks for the good news. I can't explain why doing the test improved things, maybe the control computer sensed that you were 'on' to its tricks!
Roland
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QUESTION: Hi Roland,,
Same car 94 chrysler NY 3.5 engine. Most people have problems starting their cars..when they are hot..Well in my case my car has a hard time starting in the morning. It's almost like she has a carbureator and loads up and floods out as soon as I start the engine. I either have to hold the pedal down 1/2 way or all the way to get her started. After the initial start of the day, I have no problems otherwise. The next morning it starts all over again. Just had platinum plugs put in and she has 188K miles. Is this a new one for you?
AnswerHi Linda,
The cold start problem is probably related to a fuel mixture error. There are several possible reasons that can be diagnosed by doing a self-readout of the engine controller computer: with your ignition key turn "on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the check engine light which will be "on" to begin to flash, pause, flash, etc. Count the number of flashes before each pause. Then repeat to assure an accurate set of counts. Then combine the counts in pairs in the order of appearance to form the 2-digit fault codes. The last code will be 55 which means end of readout. The other codes can be translated at www.allpar.com/fix/codes.html
or write me back with the code numbers and I can advise what they mean and what to do about each.
Roland
