Test Ad: Heating Ventilation Air Conditioning Controller Illumination Inoperative
NOTE:
Perform all voltage and resistance tests using a Digital Volt-Ohm Meter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.
- Turn ignition switch to LOCK position. Disconnect Heating Ventilation Air Conditioning (HVAC) controller 2-pin harness connector C294b. See Fig 1. Turn headlight switch to ON position. Rotate headlight switch thumbwheel to brightest position. Measure voltage between ground and HVAC controller harness connector C294b terminal No. 2 (Light Blue/Red wire). If battery voltage exists, go to next step. If battery voltage does not exist, repair open circuit in Light Blue/Red wire between HVAC controller and central junction box fuse No. 37 (15-amp). For INTERIOR LIGHTS circuit identification, see WIRING DIAGRAMS . After repair, test system for normal operation.
- Turn headlight switch to OFF position. Measure resistance between ground and HVAC controller harness connector C294b terminal No. 1 (Black wire). If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open circuit in Black wire between HVAC controller harness connector and ground point G204. Ground point G204 is located behind center of instrument panel. See Figure. For INTERIOR LIGHTS circuit identification, see WIRING DIAGRAMS . After repair, clear DTCs, repeat self-test and check system for normal operation.
- Check and replace HVAC controller indicator light bulbs as necessary. See INDICATOR/WARNING BULBS under REMOVAL & INSTALLATION. After repair, clear DTCs, repeat self-test and check system for normal operation.