Rear Defogger Switch: Testing and Inspection
Testing With Scan ToolUsing a DRB III(R) scan tool, refer to Body Control Module; Testing and Inspection for related diagnostic Information.
Testing Without Scan Tool
NOTE: For circuit descriptions and diagrams of the rear window defogger (EBL) system, refer to WIRING DIAGRAM INFORMATION.
1. Remove the A/C-heater control from the instrument panel.
2. Using a ohmmeter, check for continuity between the ground circuit cavity of the defogger switch wire harness connector and a good ground. There should be continuity. If OK, go to Step 3. If not OK, repair the open circuit as required.
A/C Heater Control - Rear View:
3. Check for continuity between the ground circuit terminal and the rear window defogger relay output terminal on the back of the A/C-heater control. There should be momentary continuity as the defogger switch is pressed, and then no continuity If OK, Refer to electrical/heated glass - diagnosis and testing. If not OK, replace the faulty A/C-heater control.