Operation CHARM: Car repair manuals for everyone.

Filament Inspection

1. Turn the ignition switch to ON.
2. Turn the rear window defroster switch on.
3. Connect the positive (+) lead of the voltmeter to the positive side of each filament and the negative (-) lead to a ground.




4. Gradually, slide the positive (+) lead from the positive side to the negative side and measure the voltage. Verify that the voltage decreases accordingly.
5. If the voltage is not as specified or it changes rapidly, the filament is damaged. Located the damaged section, then repair the filament.