Rear Window Defogger

Function Test

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

1. Check for voltage between the positive terminal and body ground with the ignition switch and the defogger switch ON.
There should be battery voltage.

•   If there is no voltage, check for:
- Faulty defogger relay.
- Faulty defogger switch.
- An open in the BLK/GRN wire.

•   If there is battery voltage, go to step 2.

2. Check for continuity between the negative terminal 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 middle of each defogger wire, and the negative probe to the negative terminal.
There should be approximately 6V with the ignition switch and the defogger switch ON.

•   If the voltage is as specified, the defogger wire is OK.
•   If there is battery voltage, the defogger wire is broken on the negative side.
•   If there is no voltage, the defogger wire is broken on the positive side.

Defogger Wire Repair

NOTE: Repair section must be no longer than one inch.

1. Lightly scour area around the break with fine steel wool, then clean with alcohol.
2. Carefully mask the broken portion of the defogger wire with cellophane tape.

3. Using a small brush, apply heavy coat of silver conductive paint extending about 1 /8 in. on both sides of the break. Allow 30 minutes to dry.
NOTE: Thoroughly mix paint before use.

4. Check for proper operation with a voltmeter (approximately 6 V at the mid-point).

5. Apply a second coat of paint in the same manner. Dry 3 hours before removing tape.