C4 Air Conditioning
Burning Brakes
Joined: Nov 2002
Posts: 807
Likes: 21
From: Los Altos CA
Re: C4 Air Conditioning (rlgreen@vwb.com)
On my '90 with auto air cond, the system would not respond to any of the buttons and blew out hot air at a high fan speed. The problem was with the "programmer", the part of the control system that is under the dash. I replaced it with a used unit and the problem was solved. If your buttons and fan speed controls still work but the temperature is wrong, your problem is different from mine.
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
Re: C4 Air Conditioning (rlgreen@vwb.com)
Hi rlgreen, I don't know if my 88 C68 climate control is the same as your later model one - here's a link to my post about how I fixed mine -
http://forums.corvetteforum.com/zerothread?id=606777
S'nut
http://forums.corvetteforum.com/zerothread?id=606777
S'nut
Instructor
Joined: Aug 2003
Posts: 107
Likes: 0
From: Aurora OH
Re: C4 Air Conditioning (white90conv)
(Chevrolet Corvette C4-1990 / RPO C68 Electronic Air Conditioning)
I've been having trouble with the push buttons on my HVAC control panel working properly for the past few years. Intermittent ability to access fan speeds, temperature setting, and modes. Most times, it will stay in a mode for hours until it decides to accept new inputs. During this time, unable to adjust temperature or fan speeds, as well as change modes. Currently unable to enter diagnostic mode by holding the two fan speed buttons.
I believe the programmer is my problem also.
1) Is there a test that I can perform on the programmer to determine if it is the cause of my problems?
2) Are the units repairable, or do they require replacement?
If repairable - can you recommend a repair station that I could send my unit to for service?
3) Is the unit exclusive to Corvette or is it used in other GM makes and models?
4) Is there a source for certified used programmers?
5) GM oem part #
6) Retail price $
Appreciate any input -
Thanks
I've been having trouble with the push buttons on my HVAC control panel working properly for the past few years. Intermittent ability to access fan speeds, temperature setting, and modes. Most times, it will stay in a mode for hours until it decides to accept new inputs. During this time, unable to adjust temperature or fan speeds, as well as change modes. Currently unable to enter diagnostic mode by holding the two fan speed buttons.
I believe the programmer is my problem also.
1) Is there a test that I can perform on the programmer to determine if it is the cause of my problems?
2) Are the units repairable, or do they require replacement?
If repairable - can you recommend a repair station that I could send my unit to for service?
3) Is the unit exclusive to Corvette or is it used in other GM makes and models?
4) Is there a source for certified used programmers?
5) GM oem part #
6) Retail price $
Appreciate any input -
Thanks
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
Re: C4 Air Conditioning (Spinman)
Did you check out the link I posted above ?
My keypad contacts were dirty/loose and I’m fairly sure that is your problem, it’s certainly worth checking.
The keypad contacts are the same as in a TV remote and can be cleaned with surgical alcohol/methylated spirits. The back panel of the front unit is held on with melted plastic posts and as these break away with age the back gets slightly loose – so that the contacts are not close enough to work. – It’s all in my post.
S’nut
My keypad contacts were dirty/loose and I’m fairly sure that is your problem, it’s certainly worth checking.
The keypad contacts are the same as in a TV remote and can be cleaned with surgical alcohol/methylated spirits. The back panel of the front unit is held on with melted plastic posts and as these break away with age the back gets slightly loose – so that the contacts are not close enough to work. – It’s all in my post.
S’nut
Instructor
Joined: Aug 2003
Posts: 107
Likes: 0
From: Aurora OH
Re: C4 Air Conditioning (Stingraynut)
When I discussed the problem (via email) with a tech - he thought the problem was most likely the programmer. If I remember the discussion correctly - the fact that the problem is intermittent and affects a variety of buttons - he felt that it was the programmer as opposed to the control panel.
I guess it would be a good Saturday morning project to remove the control panel and try the cleaning the unit before advancing on to the programmer.
Just in case - still would like info on a source for a new / certified used unit - or perhaps a R&R station...
I guess it would be a good Saturday morning project to remove the control panel and try the cleaning the unit before advancing on to the programmer.
Just in case - still would like info on a source for a new / certified used unit - or perhaps a R&R station...
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Advanced
Joined: Sep 2001
Posts: 70
Likes: 0
From: Jacksonville Fl
Re: C4 Air Conditioning (rlgreen@vwb.com)
I had the same problem on my 88 . I found the problem was a set of vacum solenoids under the dash by the gas pedal . This was causing the heater door to stay open all the time. This part was defective. Cheap Fix!
1990, 1996, air, auto, c4, conditioning, corvette, covette, dash, electronic, heater, info, opreration, program, programmer, site, technical
