Rear Defogger: Testing and Inspection

(For models with power door locks)
Symptom: Rear window defogger does not activate, or does not go off after activating.




(For models without power door locks)
Symptom: Rear window defogger does not activate, or does not go off after activating.

Electrical Components Inspection





Rear Window defogger relay
Check continuity between terminals (3) and (5), (6) and (7).





Rear Window defogger switch
Check continuity between terminals when rear window defogger switch is pushed and released.





Filament Check
1. Attach probe circuit tester (in volt range) to middle portion of each filament.





^ When measuring voltage, wrap tin foil around the top of the negative probe. Then press the foil against the wire with your finger.





2. If a filament is burned out, circuit tester registers 0 or 12 volts.




3. To locate burned out point, move probe to left and right along filament. Test needle will swing abruptly when probe passes the point.