Rear Window Defogger 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 along filament. Tester needle will swing abruptly when probe passes the point.