I've been having off and on issues with my electronic heat /ac control.
last night when i got in the car, the a/c blew a little too cool for my wife, so...I raised the temp. At that point, it wouldn't shut off, go back to auto or lower the temp, only raise it. I could only get it to blow from the floor and dash or dash only. Got home parked in the garage. Tonight, disconnected the battery, re-set the computer , everything back to normal except can't lower the temperature.
Any ideas?????

 

Remove the a/c control head out of the dash and get some electrical contact spray and spray it on a Q tip and clean the two row of pins that plug into the wiring harness connector. Then pull on the circuit board latch on each side at the rear of the control head so you can pull on the front and remove the front panel with the circuit board attached. Use your Q tip and clean the contact bars on the circuit board and put the control back together and re-install it in your car. Let me know if everything works ok.

 

I've had similar issues, thanks for the advice...

 

I did too, I have the same problem too. I just smack the side of the dash and it works right till the next day. Y eah I know, WTF is this idiot doing smacking his corvette.

 

Sounds like you may have multiple problems or maybe an intermittent ground, though usually a Control Panel that won't change it's display is a funky Control Panel. The Processor for your Year (assuming it's a 94) is the Programmer. It receives signals from the Dash Controls via serial data lines and based on those inputs (and signals from the Inside and Outside Temp Sensors), sends low voltage signals to a Blower Module to control Blower Speed, directs vacuum to various Solenoids to control air flow, and controls voltage to an electric motor that moves a door directing air to the evaporator and/or heater core. It also communicates with the PCM which controls compressor engagement and the CCM so that it's built in diagnostics can be accessed with a scanner. Problems are generally indicated by a flashing LED on the Control Panel (see Tech Tips for how you access any codes without a scanner) and if there is a problem, nothing will work until it's memory is cleared (accomplished by disconnecting and reconnecting the battery). It's best to test the system with a bi-directional scanner through the CCM link. That will emulate the Control Panel and verify that the Programmer is able to do what it's suppose to do. So if cleaning the contacts doesn't work, I'd find out what a dealer wants to hook one up - may save you from replacing unnecessary parts.