Heated Glass Element Relay: Testing and Inspection

Rear Window Defogger Relay:

Relay Terminals:

Rear Window Defogger Relay Test:

The rear window defogger relay is located in the fuse/relay block along side of the speaker amplifier in the rear cargo area. While this relay uses a ISO relay output terminal configuration it differs from a conventional relay since it incorporates the timer for the rear window defogger as well.

Remove the rear window defogger relay from the fuse/relay block to perform the relay tests. Refer to the Rear Window Defogger Relay Test table and Wiring Diagrams for pin locations.
1. Using a Voltmeter, test for Be+ in the following terminals.
a. Terminal 8 should read within one of battery voltage. If OK, go to Step b. If not OK, check fuse 3 in the fuse/relay block.
b. Terminal 11 should read within one of battery voltage, with the ignition switch in the RUN position. If OK, go to Step 2. If not OK, check fuse 8 in the fuse block.

2. Using a Voltmeter, test for B- (ground) in the following terminals. Place the positive lead of the voltmeter in terminal 8. Briefly, touch the voltmeter to a good ground and observe that the voltmeter reads within one volt of battery voltage. Using the negative lead of the voltmeter, test for B- in the following terminals.
a. Terminal 7 should read within one volt of battery voltage. If OK, go to Step b. If not OK, repair the Z1 circuit (relay ground) to ground.
b. Terminal 9 should have continuity to ground when the rear window defogger switch is pressed. If OK, go to Step 3. If not OK, refer to Rear Window Defogger Switch Test.

3. To test terminal 10 remove relay and connect a ohmmeter to the B+ connector on the left side of rear window defogger grid terminal. If there is continuity, replace relay. If no continuity repair C15 circuit as necessary.