Grid Filament Test
- With ignition on, turn on rear window defogger. To locate breaks in grid wire filaments, connect positive lead of voltmeter to middle portion of each filament. Connect negative voltmeter lead to ground.
- If a grid wire is broken, voltmeter will indicate either zero or battery voltage, depending on location of break. If grid wire is not broken, meter will indicate about 6 volts. To locate break, move probe along grid wire until meter needle moves abruptly.