Filament Inspection

Switch the ignition ON.
Turn the rear window defroster switch on.
CAUTION:
- Directly touching the rear window defroster filament with the lead of the tester could damage it. Wrap aluminum foil around the end of the lead and inspect the filament by touching it with the foil.
Connect the positive lead of the tester to the positive side of each filament and the negative lead to ground.

Gradually slide the positive lead from the positive side to the negative side and verify that the voltage decreases accordingly.

If the voltage changes rapidly, the filament has a malfunction. Repair the filament.

Fig 1: Inspecting Filament By Touching It With Foil

Courtesy of MAZDA MOTORS CORP.

VOLTAGE REFERENCE CHART

Measured part	Voltage (Reference)
(1) to (2)	Approx. 11 V to 0 V

Fig 2: Sliding Positive Lead From Positive Side To Negative Side

Courtesy of MAZDA MOTORS CORP.