Rear Window Defogger Inspection

Switch the ignition ON (engine off).
Turn the rear window defogger switch on.

Fig 1: Wrapping Aluminum Foil Around End Of Lead
Courtesy of MAZDA MOTORS CORP.
CAUTION:
- Directly touching the rear window defogger with the lead of the tester could damage it. Wrap aluminum foil around the end of the lead and inspect the rear window defogger by touching it with the aluminum foil.
Connect the positive lead of the tester to the positive side of each rear window defogger 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.

Fig 2: Measuring Voltage Between Rear Window Defogger
Courtesy of MAZDA MOTORS CORP.
- If the voltage changes rapidly, the rear window defogger has a malfunction. Repair the rear window defogger. (See REAR WINDOW DEFOGGER REPAIR .)

MEASURED PART	VOLTAGE (REFERENCE)
(1) to (2)	Approx. 11 V to O V