Question
Control Head
Ok...this may be lengthy, but I will try to explain everything the best I can. 1) My husband is a automotive technician. However, he is NOT a Chrysler expert at all. 2) We have been having issues with our air conditioning and "fixing" it slowly as finances (and hubby's time) allows. First issue was the compressor died. Replaced that and receiver/dryer. We also had a VERY slow leak and used 134A with leak seal and it held for well over a year. However, after the compressor died and we replaced it, the air conditioning has not worked properly since. Hubby filled with coolant after the compressor replacement and has checked it since and it is full. However, the compressor at one point was making a sort of roaring noise. That was right around the beginning of winter (and holiday season, i.e. extra expenses) so we just didn't use it and are just now getting back to addressing the issue. So when he started using the air again he decided maybe the roaring noise could be a strain on the compressor because of a restriction possibly caused by the sealant in the 134A so he "blew out" everything he could to make sure there was clear passage. Since that time after putting everything back together, if he turns on the air conditioning, it will not blow cold at all and he says he doesn't hear the compressor turning on. I asked if he checked all his connections and he said yes, but went back and checked anyway...all good. As a side note, he swears at times if he is running the "air" it will get cold briefly, but he is not sure why or if the compressor is coming on when he feels this supposed "cold air." He now believes that possibly the control head has finally died. That has always been another issue since we purchased the van (used). The lights on the control panel blink on and off even when the air was working perfectly. I tried the "reset" thing on it once and the diagnostic test (found these on the internet). To be honest I can't remember the results of the diagnostics and the reset only worked VERY briefly. Hubby was supposed to look into the diagnostics result, but he never did and since the air was working at the time we just forgot all about it.
So my question is two fold...1) do you think it could be the control head that is the issue now? and 2) in searching for a good used control head to replace this one I have come across information saying there are 3 different plugs on the control head....black, yellow and blue. From what I have read so far, this has something to do with the year of the vehicle and the plugs ARE NOT interchangeable because of the location of the pins. However, reading further from the same information, it says a control head that has a black plug in should work with our vehicle year, make and model. WTF??? So the second question is whether or not the plug color makes a difference and if I need the EXACT same control head or what that says it is interchangeable between multiple model years?
I hope this was not too lengthy and was understandable. Thanks in advance for your help.
Paula
AnswerHi Paula,
The manual has 40 pages about the main AC/heater system and about 10 pages of wiring diagrams. But for diagnosis of the problem only 10 pages are sufficient. The unit as you know has a self-diagnostic capability which turns out to be quite helpful but is also detailed and would best be accomplished if you had those specific pages to work with. I can photocopy and postal mail those to you for a cost of $1.50 which you can later send me back three postage stamps to cover my cost.
As to the plugs, there are 2 sockets in the control unit, a blue 21-pin and a black 10-pin.
The three plug model applies to a unit that is called automatic temp control and became available after '98 (my next manual shows it and that is for the '02 model year, and also by then the conventional unit like the one you have still had two plugs but they were 20 and 10 pin each). The '97 and '97 are different also, and I can't speak to the '99-'01 model years for lack of manuals. So if you opt to replace the control I would stay with a '98.
But before giving up on the present control unit I would suggest you try to go through the self-diagnostics using the 10 pages. The compressor function is clearly determined by observing visually/listening while in motion and that is generally a function of having the correct pressure of coolant in the system and a functioning compressor clutch.
Once you have done that we can focus on how to correct what is shown to be the specific problem.
Let me know your postal address if you want the pages.
Roland
