Control Panel Testing

Switch ignition on, touch "75° AUTO" and observe L.E.D.'s come on. Switch ignition on and off a few times to ensure that L.E.D.'s always light "75° AUTO". If no lights, power is not reaching control panel. Check A/C fuse and brown feed wire to control panel. If L.E.D. changes position when ignition is turned on, orange B+ feed wire may be disconnected or in wrong position, or fuse may be blown.

Fig 1: Heater and A/C case Assembly Showing ETCC Components

Courtesy of GENERAL MOTORS COMPANY

Fig 2: Heater and A/C Case Assembly Showing TCC Components

Courtesy of GENERAL MOTORS COMPANY

NOTE: Pin "B" should have power at all times, even when ignition is off. Check center connector or rear of control panel for proper wire locations and engagement. If above test is unsatisfactory, replace control panel.