94 PA climate Control problems

[Eric54]

My 94 PA has a problem with the climate control. In the winter it doesn't blow out the correct vents and doesn't keep the car warm enough. In the summer when you start the car it blows very hot air out the vents for about 30 seconds, then you hear some doors moving and you get normal air conditioning for the rest of the drive. In all cases the temp flashes after about 30 seconds for a couple of minutes. I have read the threads about getting the diagnostic codes but I can't get mine to do anything when I press "off" & "temp up" except turn the temp up. I have a parts car and have swapped out the "control" unit (the part with the buttons) and the "slave" unit (the part that has the vaccum connector and sits in front of the ECM) and no change. Is there another unit or "Box" that is part of the climate control system. BTW the climate control worked fine in the parts car. Why can't I get the codes? the car has almost 112K. also this problem quit for awhile this summer but after I disconnected the battery and put a new ECM in it started messing up again. I since tried putting original ECM back in but it still messed up. I don't think it's related but I replaced the ECM because the car was cutting out like a power problem, sometimes dying, somtimes just cut out and then catch again, really annoying. Swapping ECM with parts car ECM stopped problem but gave me parts cars problems, so bought rebuilt ECM car runs fine. sorry this ran long, hope you can help, Thanks,

Eric

[HotZ28]

In the summer when you start the car it blows very hot air out the vents for about 30 seconds, then you hear some doors moving and you get normal air conditioning for the rest of the drive.

That is the way the system was designed. It should blow warm the first 30 sec. to clear any humidity out of the system. This was a carry over from the previous system design.

Unfortunately, 1994 was the transitional year to the new AC controller and the luxury or checking codes and resetting codes were gone! If you have a flashing of the control display, it is trying to tell you that a code has set. The only way to retrieve the codes is with a scanner designed for that purpose. Most reputable AC shops can scan the codes and of course, as a last resort, the dealer can.

Have you checked the blend door operation, the one above the programmer? The programmer is the unit above the ECM. (The one you changed)

What model (year) “parts car” are you removing the parts from? 1994 parts, are not interchangeable with previous years!

[Eric54]

I agree that it blows warm air down to the floor to clear the air for a few seconds, that's how it works when it's working correctly. when I get the code, it blows full hot air out the air conditioning vents right in your face for a full 30 seconds, not pleasant! the doner car is also a 94 PA. Yes we have watched the blend door shaft operation. It starts in the cool left position then goes full right position where we get full hot air in the face then about 30 seconds later it goes back full left. After 30 sec. we can increase the temp and the blend shaft will go to a mid position. is there any other component we can try from the doner car? Thanks for the info on the codes. any chance a Snap-On MT2500 can read those codes?

Thanks again,
Eric

[ruffo66]

Eric54 Try this,(I'ts worked for me on my 95 PA)open up the glove box and disconnect the the blend door shaft.Start the car and turn on your climate control. Let the blend door acctuator go back and forth like it has been doing,when it stops turn your temp control to either all the way cold or all the way to hot, when the blend door acctuator reaches the position you set and stops, hold the blend door into that position(either hot or cold whichever you picked) and reconnect the blend door shaft.Play around with the temp control to see if it moves freely then shut the car off and restart to see if the blinking stopped. The blend door should not go back and forth anymore. Let us know if it worked.

[Eric54]

Thankyou Ruffo66!! that worked!This is what these sites are all about, people helping people. I am sooooo happy! Thankyou AF for making this possible. What caused this problem?, I saw another thread about a climate control problem and a reply said never unhook the battery with the climate control on. That is what I did when I put the new ECM in. Thanks again.

Eric