Heated Glass Element Switch: Testing and Inspection

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, 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 AIR-BAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN AN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

NOTE:
- The rear window defogger switch may be tested in the vehicle or out of the vehicle, on a bench.
- For circuit descriptions and diagrams of the rear window defogger system.

1. Remove the rear window defogger switch from the instrument panel, but leave the switch connected.
2. Turn the ignition switch ON.

Rear Window Defogger Switch Connector:

Defogger Switch Connector Pin Call-Out:

3. Using a voltmeter, check for battery voltage at Pin 3 of the rear window defogger switch.
a. If OK, go to Step 4.
b. If NOT OK, check fuse 7 (15 amp) in fuse block #1. If fuse is OK, check the wiring circuits.
4. Check Pin 7, with defogger switch in the On position there should be battery voltage and, no voltage with the switch in the Off position.
a. If OK, go to Step 5.
b. If NOT OK, no voltage in the On position or voltage in the Off position, replace the rear window defogger switch.
5. Press the defogger switch to the On position. The indicator lamp should come on and remain on for approximately 5 minutes.
a. If OK, install the rear window defogger switch.
b. If NOT OK, goto Step 6.
6. Check Pin 9, with defogger switch in the On position there should be battery voltage.
a. If OK, goto Step 7.
b. If NOT OK, check the wiring circuits.
7. Check Pin 10 for a good ground.
a. If OK, replace the rear window defogger switch.
b. If NOT OK, check the wiring circuits.