Electronic control has quit working, AC still blows cold.
Have been able to turn temp up, but not down.
Auto Control and OFF do not work, you can manually turn the
blower fan up & down.
Bought this car recently, it seemed to work fine. it is still blowing
cool air. Any help will be appreciated.

 

In my opinion you have two options. 1 replace the control panel. 2 take it out and clean the contacts. Chances are that you just need to clean it, there is likely dirt build up on the contacts. You would need to remove the control panel to really get it clean. Sometime you can get it well enough with compressed air.

 

 

Cleaning the contacts solves 90% of the problems.

Start by removing the lid to the arm rest center console (4 bolts). Do not remove the wires. Just tuck the arm rest lid behind the seat out of the way. Next, empty the center console contents and lift up the carpet liner inside to expose the two screws at the rear of the shifter plate. Also remove the cup holder inserts.

Remove the two rear shifter plate screws and the one screw under the cup holder. Pull the gear shifter to rear and slide the shifter console plate back exposing the screws attaching the bottom of the climate control panel/radio trim plate. You should not have to remove the gear shift ****. There is room to move the shift console back enough to see the screws.

Remove the screws from the bottom of the climate control trim plate.
Next, remove the central A/C vent (2 screws) above the climate control.
When that’s done, you’ll see a third screw that’s holding the top of the
radio/CC trim piece in that needs to be removed.

After that trim piece is off, you’ll notice the two bolts holding the CC unit in place, remove them. The unit will now slide straight out, and you can unplug it from the wiring harness in the rear by squeezing the top of the plug to release the plug clip and work the plug out.

Take the CC unit inside to a clean well lit place to work on it. There will be 6 “small” 3/16” bolts that need to come out. One tip I can give you is this
- when you’ve get all 6 removed (two on the back surface, and 4 around the perimeter), point the face of the CC unit towards the ground while separating the two halves - you don’t want the
- individual buttons to fall all over the place. With that complete, you will be able to remove the internals. There will be 2 circuit boards joined like a “T”. They simply unplug by pulling the two of them apart. Disconnect the small wiring harness and set the larger of the two circuit boards aside.

Holding the control button unit CAREFULLY remove the 4 light bulbs (will look like grey plastic plugs from the back) with a skinny flathead screwdriver - they should take about a 1/4 turn counterclockwise to “unlock.” There are two small 3/16” screws in the center of the circuit board holding it to the button holder case, remove them. Lift off the green circuit board and gray rubber contact pad from the buttons. Lay the button holder off to the side. Do not turn it over or the buttons will fall out.

Proceed with cleaning the button contacts on the green board and be able to tell what I’m talking about when you have it apart) with a soft” clean pencil eraser, and then give it a good wipe with some Isopropyl Alcohol pads. After it’s dry re-assemble and head back to the car, plug it in to the wiring harness for a test - it should work as new!

Re-assemble all other trim pieces, etc. in the order they were removed. Shouldn’t take more than an hour.. .maybe a tick more depending on how careful you are. It really “IS” an easy job."

 

thanks for the help. I have worked on other items that require careful attention, and really appreciate your detailed instructions.

 

yes, the contacts make sense. this afternoon
the buttons worked !! Thank you for your help !

 

For those looking for the original post with these instructions go to:

http://forums.corvetteforum.com/show....php?t=1519199

 

thanks for the help. Our computer skills are lacking and we didn't find this post when we searched. We appreciate you taking the time and rewriting those instructions. I haven't owned corvette's since the 70's, and these C-4's are more complex. I'm not a mechanic but can follow instructions on delicate workings. What is your opinion on the Helms'
2 volume set of manuals??

 

Invaluable. Will pay for itself many times over.