FixVault

Filament Inspection

  1. Turn the ignition switch to the ON position.
  2. Turn the rear window defroster switch on.
    CAUTION:
    • Directly touching the rear window defroster filament with the lead of the tester could damage it. Wrap aluminum foil around the end of the lead and inspect the filament by touching it with the foil.
  3. Connect the positive lead of the tester to the positive side of each filament and the negative lead to ground.
    Fig 1: Measuring Defogger Filament Voltage
    G06726150Courtesy of MAZDA MOTORS CORP.
  4. Gradually slide the positive lead from the positive side to the negative side and verify that the voltage decreases accordingly.
    • If the voltage changes rapidly, the filament has a malfunction. Repair the filament.
    VOLTAGE REFERENCE CHART

    Measured part Voltage (Reference)
    (1) to (2) Approx. 11 V to 0 V
    Fig 2: Checking Voltage Of Repaired Filament
    G06726151Courtesy of MAZDA MOTORS CORP.