1992 air conditioner problem

[Jeff Z.]

The air conditioner on my '92 coupe will not blow cold air. When I start the car if the climate control system is off the "off" button blinks, and when I push the "auto" button it also blinks for about 20 seconds. Apparently the blinking light on the buttons indicate a problem with the system - maybe broader than just an AC issue. I have tried replacing AC fuses and the AC circuit breaker in the hopes of a simple fix but this did not work. Has anyone experienced this issue or have suggestions for how best to diagnose the problem?

Jeff Zachwieja (58610)

[Joe L.]

Re: 1992 air conditioner problem

The air conditioner on my '92 coupe will not blow cold air. When I start the car if the climate control system is off the "off" button blinks, and when I push the "auto" button it also blinks for about 20 seconds. Apparently the blinking light on the buttons indicate a problem with the system - maybe broader than just an AC issue. I have tried replacing AC fuses and the AC circuit breaker in the hopes of a simple fix but this did not work. Has anyone experienced this issue or have suggestions for how best to diagnose the problem?

Jeff Zachwieja (58610)

Jeff------

The controller (the in-dash component with the buttons) is notoriously problematic on these cars. So, your problem could very well be the controller. However, there may be other faults which could also cause the problem you describe.

[Jim T.]

Re: 1992 air conditioner problem

Jeff I do not know about your 1994's air conditioner, however my 1996's Service Manual has a section to trouble shoot its air conditioner. It also has a way to push buttons on the air conditioners control panel and retrieve trouble codes in a number form.

[Bill M.]

Re: 1992 air conditioner problem

Has anyone experienced this issue or have suggestions for how best to diagnose the problem? (58610)

Push the "fan up" and "fan down" buttons at the same time for about 5 seconds. Then push "auto fan" to read fault codes. 00 is OK; 09 is low freon. There are 10 fault codes possible.

[Bill H.]

Re: 1992 air conditioner problem

Yep, first retrieve the codes. And, guys on our C4 forum have had good luck cleaning the controller . 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 consol 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 consol 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 knob. There is room to move the shift consol 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 4around 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 the gray rubber. All I did was �lightly� go over the contact circuit points (you'll 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.

[Jeff Z.]

Re: 1992 air conditioner problem

Thanks to everyone that responded to my AC post. I'll check the codes as you suggest and try cleaning the controller. Probably will have some time this weekend to do so. I'll post another reply to let you know how it turns out.

Jeff (58610)

[Jeff Z.]

Re: 1992 air conditioner problem

To complete this thread, as it turns out, when I checked the codes 09 came up indicating low air conditioner coolant. I got it recharged at a dealer and it has been working great since. Although there is a minor leak I will need to get fixed.

Jeff (58610)