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


Filament repair
Window glassMazda 6 Service Manual: Windshield Defrosting and Defogging
Press the windshield defroster switch. In this position, the outside air position
is automatically selected, and the air conditioner automatically turns on. The air
conditioner will directly dehumidify the air to the front windshield and side windows.
Airflow amount will be increased.
WARNING
...
Mazda 6 Service Manual: Cooling system service warnings
COOLING SYSTEM SERVICE WARNINGS
Warning
Never remove the radiator cap or loosen the radiator drain plug
while the engine is running, or when the engine and radiator are hot.
Scalding coolant and steam may shoot out and cause serious injury. It may
also damage the engine and cooling sys ...