Heated Glass Element Switch: Testing and Inspection

REAR WINDOW DEFOGGER SWITCH
The rear window defogger control switch and timer circuit may be tested in the vehicle with or without a scan tool, such as the DRB III.

Testing With Scan Tool
Using a scan tool, refer to the proper Body Diagnostic Procedures Manual.

Testing Without Scan Tool
1. Remove the HVAC control head from the instrument panel however, do not disconnect any of the electrical connectors if possible.
2. Using a ohmmeter, check leads between Pins 5 and 1 of the HVAC electrical connector. Depress the rear window defogger button and the resistance reading should be 360 ohms (± 10%). If not OK, replace HVAC. If OK, check for the following possible causes:
- Rear window relay (EBL)
- Blown fuse
- Cut wire
- Poor ground
- Poor connection
- Defective BCM
- Bulkhead connector inoperative

Refer to Wiring Diagrams for complete circuit diagrams.