Window Defogger Grid Lines Test

Printed-Heater Line Check:

1. Run engine at 2000 rpm. Check heater element with battery at full.
2. Turn ON rear window defogger switch. Measure heater element voltage with voltmeter at rear window glass center A.
Condition good if indicating about 6 volts.
3. If battery positive voltage is indicated at A, there is a break to the negative terminal side.
Move test bar slowly to negative terminal to detect where voltage suddenly changes to 0 volts.
4. If 0 volts is indicated at A, there is a break in the positive terminal side. Detect where the voltage changes suddenly (battery positive voltage) with the same method described.