Filament Testing
- To locate breaks in the grid wire filaments, attach a voltmeter to the middle portion of each filament. Attach the other meter probe to the vertical section of the window grid.
- If a grid is broken, the meter will register 0 volts or battery voltage. If the wire is unbroken, the meter will register approximately half battery voltage. To the locate the break, move the probe along the wire until the meter needle moves abruptly.