C4 climate control problems
Thread Starter
1st Gear
Joined: Jan 2018
Posts: 1
Likes: 0
C4 climate control problems
when you turn on the motor, the climate control system works, all buttons and lights function perfectly. after about a min system locks up, defrost comes on and blows ice cold air on feet and dash, buttons and lights lock and will not respond. followed youtube video and cleaned internal board behind buttons, but nothing changed
Melting Slicks
Joined: Jan 2001
Posts: 2,996
Likes: 304
From: MOORESVILLE NC
Year is important. My 88 C68 problem was the AC/heater programmer. It tells where the air to go and will adjust hot and cold by moving a door electronically, after you push the buttons.
4th Gear
Joined: Dec 2017
Posts: 4
Likes: 0
when you turn on the motor, the climate control system works, all buttons and lights function perfectly. after about a min system locks up, defrost comes on and blows ice cold air on feet and dash, buttons and lights lock and will not respond. followed youtube video and cleaned internal board behind buttons, but nothing changed
I Hope somebody can help me and "Black C4 PC" Thanks
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 207
From: Orlando FL
I'm having the exact same problem on my 1994 corvette, if you just move the key to ON, before you run the engine, all the buttons works, and the air is blowing, If I turn the car on, after a minute, the buttons are not responding and the air is blowing by the top., the AC display show just - - - -
I Hope somebody can help me and "Black C4 PC" Thanks
I Hope somebody can help me and "Black C4 PC" Thanks
This should be the fix for you. Basically low voltage in the programmer due to weak capacitors. This is what I wrote up, how to fix it and some additional information.
Don't know about "Black C4" as to what year he has and his display indication.
1st Gear
Joined: May 2022
Posts: 1
Likes: 0
Your climate control problems
when you turn on the motor, the climate control system works, all buttons and lights function perfectly. after about a min system locks up, defrost comes on and blows ice cold air on feet and dash, buttons and lights lock and will not respond. followed youtube video and cleaned internal board behind buttons, but nothing changed
Burning Brakes
Joined: Jun 2021
Posts: 1,199
Likes: 449
From: NJ
Hey guys. My dad had the same issue with his ‘96 CE LT4. We followed the advice of several threads on the forum and cleaned the contacts. His capacitors were ok in the control unit which is mounted behind the foot pedals in under the drivers side dash. It was fixed when we replaced the soft vacuum lines in the unit with a harder material. I believe it was ‘96 only, they went with softer lines which get softer with age and actually collapse when vacuum is applied. Overall it does sound like an issue with the control until so I’d look into that.
Burning Brakes
Joined: Jun 2021
Posts: 1,199
Likes: 449
From: NJ
Link to detailed repair
http://forums.corvetteforum.com/c4-t...-repaired.html
Try this thread. This member rebuilt the control unit himself by testing and replacing the capacitors and provided information for obtaining parts as well as fairly detailed procedure.
Try this thread. This member rebuilt the control unit himself by testing and replacing the capacitors and provided information for obtaining parts as well as fairly detailed procedure.
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