FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Heated Glass Element Switch: Testing and Inspection

The control switch and timer circuit may be tested in the vehicle with or without scan tool (DRB).

HVAC Control Module Connectors:





Testing With Scan Tool
- If using the scan tool, refer to the proper Body Diagnostic Procedures.

Testing Without Scan Tool
1. Remove the control switch from console and do not disconnect control switch.
2. Using a ohmmeter, check leads between Pins 5 and 8 of the 8-way connector. Depress the rear window defogger button and the resistance reading should be 500 to 520 Ohms. If not OK, replace HVAC. If OK, check:
- Rear window relay (EBL)
- Blown fuse
- Cut wire
- Poor ground
- Poor connection
- Defective BCM
- Bulkhead connector inoperative.