QuestionHello Roland.
I hope I am not asking something that has been previously asked and answered. There are so many previous questions in the database, it would be easy to miss one. This will be a long explanation. I cannot help it. Personality disorder if you will. I hope you do not fall asleep in the middle of it.
I have VERY recently purchased a 1994 Chrysler Concorde. I am having a heater/ac problem. When I first test drove the car, it was impossible to control which vent that air would come out of, and what temperature the air would be. It would cycle around on its own, from heat to cool to defrost, etc. The dealership said it was the control panel, and he would fix it, and it was in the shop for seven days. To make a long story short, it was not properly repaired - ON PURPOSE. It was rigged to blow cold air out of the face vents only.
When I got the car home, my husband determined that the battery cable was never removed during the repair, due to the amount of corrosion present. (That might be important to know is why I mention it.) I went to the mechanic who worked on it to see if he guaranteed his work, and was told that the control panel was not replaced, and that he was told to fix it so it blew cold air out the face vents. (This is why I mentioned the lack of unhooking the battery cable. Because, if he took the existing control panel out and put it back in without doing so, even if it was good before he worked on it, it might not be anymore.) He said he had wired open some door so that cold air will come only out of the face vents, and that is all he did. A week or so later, he told another party - a spy if you will - he had replaced the compressor and a drier. I called local Chrysler dealer, trying to get a rough idea what might still be wrong, and the guy in the parts department was pretty sure he had sold an actuator to the mechanic who did the work. So, there may be a new actuator in it.
The mechanic said an ink pen had fallen behind the dash and burned up some motor. Then he said I needed a plenium box. I have yet to find proof that there is such a thing as a plenium box. So, right now what I have is an A/C that blows very cold air out of the face vents whether I want it to or not. If I turn the air off - I mean turn the whole system completely off - it will come back on by itself after a few minutes. Sometimes, when I start the car, I have the digital display on the control panel, sometimes I don't. When I have the display, I can control the blower speed, but I haven't noticed that I can control the temperature of the air coming out. It is always ice cold. And of course, I can't put it on defrost or anything like that - which is bad when it rains. Usually, during the course of my thirty minute ride to work, if the display was off when I turned on the car, it will come on, and vice versa. Again, when I have the display, I am able to turn the whole thing off, but it will come back on by itself after a few minutes, until near the end of my 30 minute drive, it is only staying off for a few seconds before coming back on, and then I lose the display and therefore all control of the blower speed, and lose the ability to turn it off. I have found a control panel on the web for $75.00, which is a pretty good price. But I don't want to buy it if I don't need it. I do know the heat worked BEFORE the mechanic got hold of this car, because when it was doing all that crazy cycling, I nearly passed out as it was about 100 degrees and the heat started blowing in my face while I was driving. So, unless he screwed it up, the thing is capable of producing heat...unless of course, I was mistaking vent air for heat. It was pretty hot that day. Lastly, I test drove this car a pretty good while, and I NEVER once had the check engine light come on, but now that it has come back from the shop, the check engine light does come on, and I am associating it with the control panel - for no other reason than intuition. I have tried a trick where you press the first two, and the last button on the top row of the climate control/source control section of the control panel, but it did not give me an error code like it was supposed to.
So, having given you all that information, here are my questions to you:
Do you think I need a new control panel, keeping in mind that it was acting up and not responding to commands before the jury rigging was done?
Do you think the control panel or something in the A/C system is causing the check engine light to come on?
Do you think the manual wiring open of the doors could be causing the control panel to act up?
If I buy a new control panel, should I wait until the doors have been unwired, and whatever is causing me not to be able to switch from face to foot to defrost, etc, is fixed before I install it?
Will it burn the control panel up to hook and unhook it with the battery cable attached. Or is unattaching the battery cable just to disarm the air bags? Is that how you disarm the air bags?
Is it possible to wire the doors open to only blow out of the vents. I have very little trust in anything this mechanic says.
Do you think I need a new blend air door thingy?
Is it possible there is some motor that has burnt up behind the dash?
Is there such a thing as a plenium box?
Do you have any idea what might be wrong, or where I should look first?
Lastly, any advice on taking out the dash. I understand that it is held in by clips, and any advice on procedure in order to keep from breaking a clip would be appreciated.
Any other advice you have, or any answers to questions that you see from reading what I have told you will be greatly appreciated. Thank you for taking the time to read this long message, and thank you in advance for your response.
AnswerHi Scarlet,
If all of this history took place at a Chrysler dealership then I believe that you have some leverage to get satisfaction for a botched repair job. You can start with the service manager and then the owner and then the regional corporate manager for Chrysler and if that doesn't produce reparation for the misrepair and costs that you have incurred then small claims court is the final recourse. But wiring doors open to solve an air distribution problem is clearly not "in the manual" for the proper repair of an automtic temp control system in your vehicle. Because the only person(s) who have manipulated the system are employees of the dealership, it is very difficult to diagnose what they have done and which of the present problem are due to their ineptitude. But I do know that the system is complex in that involves electrical and vacuum controlled actuators, temperature sensors, and feedback loops to the main control unit. Until all the rube goldberg fixes have been returned to status quo ante there is no way to understand how to get the system running properly, what needs to be replaced, etc. So that would be my suggestion as to how to approach this: seek redress from the dealership. If you don't have the shop manual for the car there is no reason for you to try and second guess what is going on with it. That is what you hired the dealership to do.
As to your specific questions:
I don't know whether you need a new panel; the electrical supply to it needs to be verified first (I believe there may be 4 different fuse supply lines to it all of which need to be working).
Yes, wiring open the doors will likely impact the function of the control unit because of the feedback loop. The control of the distribution doors is also handled by a vacuum supply line that is connected to the intake manifold of the engine so that provides a possible interconnection with their misrepair and the check engine light (more later).
It won't hurt the unit to service it without disconnecting the battery. The air bags need that sort of extra protective action if you service them.
So I wouldn't but a new control unit until everything is returned to the state in which it was when you brought it to the dealer, by them. And then see what the situation is with the unit and its power supply lines.
The blend air door and its control is part of the overall air handling unit and whether that door actuator is the problem or the control of the actuator is to be determined.
The only motors are the blower motor, and the temp sensor aspirator motor which is not behind the dash but on the front of the dash behind a grill (a very small motor).
The plenum is usually considered to be the duct work from the external air intake grill to the central unit under the dash. There is a power/vacuum module that he may have been referring to.
Most of the unit will be removable from the dash without tearing it all out. But again, this is not something you want to begin working on without a shop manual.
On the check engine light, I would fo the following:
turn the ignition key: on-off-on-off-on and leave it on (do this within an elapsed time of 5 seconds or less), then observe the check engine light which will be on to start to flash, pause, flash, pause, etc. Count the number of flashes before each pause, pair the number of flashes in the order they come out to form two digit numbers, the last of which will be 55 (two groups of 5 flashes each) which is the code for "end of code readout". Then write me back with the other two digit numbers for an interpretation. Repeat the readout as often as you like to make sure that you have the count exactly correct.
Hang in there...but demand satisfaction from the Chrysler corporate chain and if necessary a small claims court.
Roland
