Detecting Breaks in Rear Window Defogger Grid

Printed-Heater Line Check:

1. Run engine at 2,000 r/min. 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 6V.
3. It battery positive voltage is indicated at A, there is a break in the negative terminals from A.
Move test bar slowly to negative terminal to detect where voltage changes suddenly (0V).
4. If 0V is indicated at A, there is a break in the positive terminals from A. Detect where the voltage changes suddenly (battery positive voltage) with the same method described.