With key in the "on" position the dual controls work correctly, BUT when the car is started the controls are stuck between 77 and 78 degrees. The knobs rotate but the temperature just jumps from 77 to 78 back to 77. Any help would be appreciatted.
Thank you

I wonder if that's a code being set off. Do you have an LS1M or autotap?

I don't know. But when I depress both knobs at once the code comes up -00 which I found to be normal operation according to alldata.com

I used to have that on my 98 gt and loved it but had all kinds of problems with it. One time i unhooked the battery on the car when i was working on it and couldnt adjust any of the settings for ac or heat. another time i took compressed air and cleaned it out it had dust in it. just an idea. i like the standard old fashion controls. less chance for messups.

Either way we put the hammer down