C4 Climate Control Issues

[Marty B.]

My newly purchased 7K mile '93 Ruby coupe just may have spent too much time in storage. The electronic climate control head unit buttons have regressed from erratic at purchase to totally non-responsive. The unit can't be budged from its Auto setting, either w/ the temp setting up/down switches, fan buttons, etc. The A/C compressor cycles on and off (I'm in FL), and keeps the cabin quite comfortable. I just can't change any of the climate control settings.
C4 NCRS owners--
Is my problem likely confined to the head unit? If so, is this something that can be owner-repaired? How do I remove the plastic dash facia to gain access to the unit for removal? Once removed, what's the procedure for unit disassembly, electrical contact cleaning, etc.?
Any help on my problem would be most appreciated -- thanks!

?

[Joe L.]

Re: C4 Climate Control Issues

My newly purchased 7K mile '93 Ruby coupe just may have spent too much time in storage. The electronic climate control head unit buttons have regressed from erratic at purchase to totally non-responsive. The unit can't be budged from its Auto setting, either w/ the temp setting up/down switches, fan buttons, etc. The A/C compressor cycles on and off (I'm in FL), and keeps the cabin quite comfortable. I just can't change any of the climate control settings.
C4 NCRS owners--
Is my problem likely confined to the head unit? If so, is this something that can be owner-repaired? How do I remove the plastic dash facia to gain access to the unit for removal? Once removed, what's the procedure for unit disassembly, electrical contact cleaning, etc.?
Any help on my problem would be most appreciated -- thanks!

?

Marty-----


First of all, as I've said many times before, if one is going to do any service work on a Corvette, one absolutely needs to have the factory service manual. Aren't these very expensive? Yes, they are, but one has to have it.

As far as the controller goes, it's possible that this is your problem. These units are notorious for failing in exactly the way you describe. Replacing them is not very difficult, at all. Remove the dash fascia and it's pretty simple to remove the controller. How to remove the dash panel? It's covered in the service manual and that's the best place to get the info because it's complete with diagrams. Without them, I don't think any description I could give here would be useful to you.

Also, you need the service manual to accurately troubleshoot the problem. While the controller is a good possibility, there are others. You need to find out what the problem is before you go replacing parts.

I don't know of any way to service these modules. Basically, they were not designed for field servicing. It's very possible to rebuild them, but I think it's an operation for specialized service facilities with the equipment, manuals, and experience to do it. When GM had these available, they were sold with core deposit and all of those sold through GM were "officially" remanufactured units (although many were actually new but they needed to be called "remanufactured" in order to get the cores back).

The last sentence of the above paragraph implies your most difficult challenge. These units are GM-discontinued and I do not know where to obtain one. However, the part you're looking for is GM #16162118.

[Don G.]

Re: C4 Climate Control Issues

Marty

As always, Joe's reply is excellent. I removed my radio to repair the cd player by following the service manual. The directions and illustrations are essential.

You can find the two book set for '93 on ebay for $45.00 to $100 most any time.

You may want to consider checking out the operation of the radio unit and perhaps getting it rebuilt at the same time. They also are notorious for failing. Most reputable radio repair shops can replace the tape player/ cd unit and also check out the radio operation at the same time.

[Tom H.]

Re: C4 Climate Control Issues

Like the earlier post stated. Probably the control head in the dash. Easy replacement. Done a hundred of them !!

Good advise picking up the manual set. Good luck with the car. Sounds like a nice one !!!

[Marty B.]

Re: C4 Climate Control Issues

Thanks -- I'd been looking at svc manuals on eBay, just hadn't bought any yet. Guess I need to get 'er done!