Heated Glass Element Switch: Testing and Inspection

The rear window defogger switch may be tested in the vehicle or out of the vehicle, on the bench.

In-vehicle Testing
1. Remove the switch from the instrument panel but leave the switch connected, refer to Instrument Panel and Systems, Auxiliary Switch Bezel Removal and Installation.
2. Turn the ignition switch ON.

Rear Window Defogger Switch Harness Connector:

3. Using a voltmeter, check for battery voltage at Pin 1 and 2.
a. If OK, go to Step 4.
b. If NOT OK, check fuse 7 in the fuse block and the 40 Amp cartridge fuse in the Power Distribution Center (PDC). If fuses are OK, check wiring circuit.
4. Check Pin 5, with switch in the ON position there should be battery voltage and no voltage 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 switch.
5. Press switch to ON position. The indicator lamp should come on and remain on for approximately 10 minutes. If the indicator lamp fails to light or no voltage is present for approximately 10 minutes. Replace Rear Window Defogger Switch. Refer to Instrument Panel and Systems, Auxiliary Switch Bezel Removal and Installation.

Bench Testing
1. First remove switch. Refer to Instrument Panel and Systems, Auxiliary Switch Bezel Removal and Installation.

Rear Window Defogger Switch Connector:

2. With switch removed from vehicle, use a jumper wire and connect a 12 volt supply to Pin 1 and 2. Using a third jumper wire, ground Pin 3. Refer to and the Rear Window Defogger Switch and Harness Connector Pin Call-Outs table.
3. Follow the same procedures used for IN-VEHICLE TESTING, except for step Step 2.