AC climate controller bad?
Thread Starter
Cruising
Joined: Jun 2009
Posts: 11
Likes: 0
AC climate controller bad?
My air conditioner electronic controller unit has been giving me problems lately.
The buttons would not work when pressed or sometimes the screen would just be 2 lines.
I would turn off the car when I got somewhere, and when I got back in, it would work just fine.
I followed the intructions for cleaning it, and put everything back together.
Now, it comes on, and the buttons work, for about 10 seconds, then the fans shut off, and no buttons on the unit work.
This happens every time I start the car.
Is the unit itself bad, or should I look somewhere else?
1994 coupe.
The buttons would not work when pressed or sometimes the screen would just be 2 lines.
I would turn off the car when I got somewhere, and when I got back in, it would work just fine.
I followed the intructions for cleaning it, and put everything back together.
Now, it comes on, and the buttons work, for about 10 seconds, then the fans shut off, and no buttons on the unit work.
This happens every time I start the car.
Is the unit itself bad, or should I look somewhere else?
1994 coupe.
Drifting
Joined: Nov 2005
Posts: 1,324
Likes: 5
From: Charlotte NC
A friend had similar symptoms on his '91. He could use the unit for about 10 seconds or so after starting the car but then it would 'lock' into whatever setting the unit was on. We finally traced it to the a/c programmer unit under the driver's dash after swapping the head unit and blower control unit with no luck.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Controls communincate with the Processor or Programmer over serial data lines so a bi-directional scanner via the CCM link is used for diagnosis. That will emulate the Controls and if the system works, it's the Control Panel. However, since your Panel is dark or just 2 lines, sounds like the Controls are toast. To be sure, use a Scanner or find a Dealer who knows electronic controls and has the Scanner - shouldn't be more than an hour on the flatrate chart.
Drifting
Joined: Nov 2005
Posts: 1,324
Likes: 5
From: Charlotte NC
I don't know of any way to test the programmer. We just swapped components until it was resolved since there didn't appear to be any diagnostics for the electrical portion of the system. Helps when you have a buddy that strips dead Corvettes.
