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Heated Glass Element: Testing and Inspection

Rear Window Defogger

Function Test


NOTE: Be careful not to scratch or damage the defogger wires with the tester probe.




1. Check for voltage between the positive terminal (A) and body ground with the ignition switch and defogger switch ON.
There should be battery voltage.
- If there is no voltage, check for:
- a faulty defogger relay.
- faulty window antenna coil.
- an open in the BLK/GRN wire.

- If there is battery voltage, go to step 2,

2. Check for continuity between the negative terminal (B) and body ground.

If there is no continuity, check for an open in the defogger ground wire.

3. Touch the voltmeter positive probe to the halfway point of each defogger wire, and the negative probe to the negative terminal. There should be about 6 V with the ignition switch and the defogger switch ON.
- If the voltage is as specified, the defogger wire is OK.
- If the voltage is not as specified, repair the defogger wire.
- If it is more than 6 V, there is a break in the negative half of the wire.
- If it is less than 6 V, there is a break in the positive half of the wire.