My climate control function buttons on my ’96 worked intermittently until this summer when all of them stopped. I did a forum search and found instructions that helped me remove the climate control box and clean the internal button contacts. Thank you, thank you thank you! It took an hour and works like new now. This is a really “easy” do it yourself fix and sure beats the dealer $375 charge.
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 consol 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 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 ****. 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.
This is a great post for a full cleaning, but I get a little paranoid about any major electronics disassembly. I wonder tho if you can avoid the whole disassembly thing by using a little FM Tuner cleaner, or similar electronics cleaning spray, by spraying with the thin WD-40 type straw directly into the unit from the front at the problem button? Anybody try this as a first quick fix? It may get to the dirty contact(s) and dissolve the dirt. Thanks.
WD40 is generally not good for electrical contacts, and it really is not recommended for delicate plastics. Also, WD40 attracts dirt after awhile, which is the cause of most electrical connection issues.
I have not performed the above task, but have done similar fixes to other electronic swicthes and connections by using contact cleaner and pipe cleaners and, or QTIPs. If you get the right pipe cleaners, they are slightly abrasive, and soaked in contact cleaner they do a great job at scrubbing contacts clean. QTIPs work, but are less abrasive. If it is really corroded, soak brown paper grocery bag material with contact cleaner and 'sand' away the corrosion. For underhood terminals, and or spade lug type connectors, I soak these in contact cleaner and try to stuff some brown bag material in the connector to shine up the surface. Again, pipe cleaners work well here, too.
One word about contact cleaners, or TV Tuner cleaners; MAKE CERTAIN THAT THEY ARE SAFE FOR PLASTICS! Some say "safe for most plastics", but they might melt some delicate nylon switch.
Personally, I use DeOxIt and have never had it damage anything. My second choice is Radio Shack's TV Tuner spray (believe it, or not). Otherwise, most brands like Tech Spray, or Blue Shower have damage plastics and I am wary of those brands.
If you want to 'flush' out a switch on the console, or dash, again make sure the contact cleaner is safe for plastics, spray the switch openings, and cycle the switch back and forth many times. Then repeat.
Just wanted to add my two cents here. Take care, Bill
"WD40 is generally not good for electrical contacts, and it really is not recommended for delicate plastics. Also, WD40 attracts dirt after awhile, which is the cause of most electrical connection issues."
Thanks - good info, I will try to find the right cleaner at Radio Shack, they must have something that will work or will try your "DeOxIt" suggestion. Where did you get it?
Great information so far, I'm adding some additional information from a past write up I have done. Thought this tid bit of information might be of some help to others.
My C68 worked well most of the time. Sometimes it would put me on ignore and not respond to some of the buttons and the green LEDs might not light as bright as it should.
This should be fairly simple for most.
I removed the cover and inspected the solder on the main circuit card. It is well made and coated and the solder looked great. I removed the main board from the vertical board by un-plugging it carefully. I inspected the pins and saw where they could be cleaned up. Also inspected the solder on the smaller vertical board and decided the re-solder the connections on the LEDs. This is a quick re-flow with a small amount of additional solder added. (Be gentle when working on everything and observe some ESD practices).
I used very light emery cloth to lightly clean the sides of the pins where the contacts are made on the vertical board. Then I used a cleaner on the pins to finish up and blew off with clean air. I also squirted some cleaner into the connector of the main board and blew off with clean air.
I then re-assembled the climate control and installed back in the car. I didn’t know quite what to expect for I felt like I did not do much or really find anything solid.
The system works better than it has ever before. It always responds to me and has been for months now and confidence is building in the repair. Going down the road is nicer now because the distraction is less due to the buttons work when I now press them.
There is a guy on Ebay that seems to have a lot of the 97-00 climate control head units - they are cheap and come with warranty. I think that they were rebuilt "cores", so probably do not have the innards of the OEM part. But for $50?? What a deal - and if it works it works! Anyone out there know of anyone selling the C4 units that seem to go bad?
Yes this type of thing makes this forum priceless. I have experienced issues with mine occasionally. I had some time this afternoon and decided to clean the CC contacts. It went well and seems to working fine now. Not a hard job at all and takes about an hour. Socalman, can we make this part of the DIY sticky if is not already?
Thank you very much TiIngot for your instructions on the AC control button problems. You saved me lots of $$$. I was ready to buy a new control, but found your instructions, followed them to the letter and the problem of buttons not working is solved.
Has anyone ever tried this with early year C68 setup? I took mine out a couple weeks ago and decided not to pull the case apart. It had dozens of plastic pins melted(?) to hold it's chassis together.
I probably could have pulled all the nubs off and gotten the thing to come apart (so I could clean the buttons) but I couldn't think of a great plan for reassembly. (No way to replace the nubs -- guess I could have glued it back together.)
Also, wasn't sure if I was going to have any issues -- though I've cleaned older buttons on prior vehicle using a similar technique.
After having everything work again, my fan controls seem a bit unresponsive at times. Usually, every button works pretty well -- esp for a 22yr-old car.