Grid Filament Test
CAUTION:
Directly touching grid filament with test lead will damage it. Wrap aluminum foil around end of test lead and test grid filament by touching it with foil.
- Turn rear window defogger on. Attach a voltmeter probe to middle portion of filament. See Fig 1 . Attach other voltmeter probe to vertical section of window grid.
- If wire is not broken, voltmeter will register about one half of battery voltage. If a grid is broken, voltmeter will register zero volts or battery voltage, depending on whether grid is broken between test leads or outside test leads. To locate break, move probe along wire until voltmeter needle moves abruptly.