Heated Glass Element Switch: Testing and Inspection

REAR WINDOW DEFOGGER SWITCH

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN AN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

Refer to Wiring Information for rear window defogger system circuit descriptions and diagrams.

1. Disconnect and isolate the negative battery cable.
2. Remove the A/C-heater control from the instrument panel and disconnect the wire harness connector from the rear window defogger switch.
3. 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 4. If not OK, repair the open circuit as required.

A/C Heater Control - Rear View:

4. 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. If not OK, replace the faulty A/C-heater control.