Heated Glass Element Switch: Testing and Inspection

The rear window defogger switch may be tested in vehicle or bench tested. In vehicle testing is accomplished in the following manner:
1. Remove the switch from the instrument panel but leave the switch connected, Refer to Instrument Panel, Gauges and Warning Indicators/Instrument Panel replacement.
2. Turn the ignition switch ON.

Systems Electrical Circuit:

Rear Window Defogger Switch:

3. Using a voltmeter, check for battery voltage at Pin 3 and Pin 4.
a. If OK, go to Step 4.
b. If NOT OK, check fuse 8 in fuse block and the 30 Amp maxi fuse in the Power Distribution Center (PDC).
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/relay module.
5. Press switch to ON position. The indicator lamp should come on and remain on for approx 10 Minutes. If the indicator lamp fails to light or no voltage is present for approx 10 Minutes. Replace Rear Window Defogger Switch.
6. To bench test relay:
a. Using a jumper wire connect a 12 Volt batter supply, apply voltage to Pin 3 and 4. Ground Pin 2.
b. Follow the above procedures except Step 2