Heated Glass Element Switch: Testing and Inspection

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, REFER TO AIRBAGS AND SEAT BELTS/AIRBAGS BEFORE ATTEMPTING STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. Disconnect and isolate the battery negative cable. Remove the defogger switch and unplug the switch wiring connector.
2. Check for continuity between the ground circuit cavity of the 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.

Defogger Relay Switch Continuity:

3. Check for continuity between the ground circuit and rear window defogger switch sense circuit terminals on the back of the switch housing. There should be momentary continuity as the defogger switch button is depressed, and then no continuity. If OK, see the diagnosis for Instrument Cluster. If not OK, replace the faulty switch.