I have a 94 coupe with the auto climate control. Some of the buttons on it seem to be hit or miss. IE, sometimes nothing happens when increase or decrease the temperature button. Is this fixable without changing the whole thing?

My A/C and heater work fine. Just sometimest he buttons can be a little hit or miss. Usually just pressing them really hard gets it to work.

If this if a DIY job, are there any not so obvious things I should know?

Thanks

 

I had the same problem with the buttoms. It could be dirt behind were the bottoms make contact. What you can do is, take the piece out and clean the back of the buttoms or buy another unit from here or ebay. I got an almost new unit from ebay for $39.00 and is work fine now. Easy job to do. Good luck.

 

I'm having a similar problem with my 96, and the lights don't go on either.

 

Is it a code function trying to display?

Not sure if this applys or not but it is GM OBD I and II

Accessing Diagnostic Codes
For driveability and emissions problems, you can access trouble codes and sensor data the usual way with a scan tool, or you can read the information through the Climate Control Center. To enter the built-in diagnostic service mode, press the OFF and WARMER buttons simultaneously and hold until all the segments on the display panel light up. If there are any engine or other trouble codes in memory, they will be displayed.

On the 1993-'95 models (pre-OBD II), trouble codes have a letter prefix, three-digits followed by a "C" for current or "H" for history code. On the 1996 and newer cars with OBD II, the prefixes are somewhat different and the codes are four-digit numbers.

On the earlier cars, engine codes have an "E" prefix. On the later OBD II cars, "P" is the prefix for powertrain.

Other codes on the earlier cars include "I" for instrument panel, "A" for the A/C system, "R" for the air bag system, "T" for ABS/traction control, and "S" for the electronic suspension. On the newer OBD II cars, the prefixes are different. You'll see "IP" for the IPC instrument panel, "AC" for air conditioning module, "TC" for traction control, "RS" for the road suspension system, "SD" for the air bags, "PZ" for the body control module, plus other codes for other accessories such as "CC" for the cell phone or "RF" for the integrated radio.

If there are no engine/powertrain codes in memory, the display will read "No E Code" or "No P Code" depending on the model year.

To check for other system codes, press the WARMER button to scroll ahead (or OFF to scroll backward). If the PCM can't communicate with a particular system, the display will read "No X Data" where X represents the letter(s) of the system.

To clear an engine code, choose PCM mode after any codes have been displayed, then scroll to CLEAR CODE, press the HI button to select, then press the HI button again to erase the code(s).

To exit the service diagnostic mode, press the AUTO or DEFOG button, or simply turn the ignition off. This does not erase any codes.

 

Save your money. Over 90% of the problems with the HVAC control are related to dirty contacts. An easy fix!

Cleaning the Guts: https://www.corvetteforum.com/techtip...D=92&TopicID=2

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

https://www.corvetteforum.com/techtip...=118&TopicID=2

Follow the instructions and you should be okay. Hint: When reinstalling the unit DON"T OVER TIGHTEN the screws. The plastic gets brittle with age and is easily broken. Also, when disassembling the unit, place it on an old towel. That will keep loose parts from rolling off the bench onto the floor where they can be hard to find. Don't ask how I know

 

I keep getting a 404 Error when I try the links - anyone else? I have found many threads no longer exist, so maybe this is an issue?

 

Dang it! The links were there two weeks ago. Apparently they have been put into the electronic "circular file" with the new upgrade.

While not as specific detailed for removing and cleaning the control head the following link may be of some help and will give you more information than you will ever want regarding the C-68 controller.

http://batee.com/corvette/acrepair/c...oard/c68.shtml

 

[QUOTE=CStewTAMU;1566668350] sometimest he buttons can be a little hit or miss. /QUOTE]

Mine are like that and I am suspecting as others have said, dirty contacts. I am wondering though because sometimes I push the fan speed buttons, up or down and neither will do anything and then all of the sudden both will work fine. If it was just dirty contacts, why would they both start working at the same time? Nonetheless, I am going to try cleaning it and if that doesn't work, probably buy a new one for $200 on ebay. I don't think I would by a used one, it may do the same thing.

And yes, I couldn't get those links to work either.

 

Fortunately I printed out a hard copy of the instructions. I don't know who the Forum member was that wrote these up but thanks to him!


"Some of the instructions were vague so I am going to re-write them here while it is still fresh in my mind. Older dash and console disassembly may be slightly different but once the climate control box is out then I think all steps may be the same to open and clean the climate control box.

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."