LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2008 >> RX 400h AWD >> Repair and Diagnosis >> Body & Frame >> Windows >> Windshield/WINDOWGLASS >> Window Defogger Wire >> On-Vehicle Inspection
April 5, 2026: LEMON Manuals is launched! Read the announcement.

On-Vehicle Inspection

  1. INSPECT BACK WINDOW (DEFOGGER WIRE) 
    NOTE:
    • When cleaning the glass, wipe the glass along the wire using a soft and dry cloth. Take care not to damage the wires.
    • Do not use detergents or glass cleaners that have abrasive ingredients.
      Fig 1: Pressing Tin Foil
      G04967166Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    • When measuring voltage, wrap a piece of tin foil around the tip of the negative rester probe and press the foil against the wire with your finger, as shown in the illustration.
    1. Turn the ignition switch on.
    2. Turn the defogger switch ON.
      Fig 2: Checking Rear Window Defogger Wire
      G04967167Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Check the voltage at the center of each defogger wire, as shown in the illustration.

      Standard voltage 

      VOLTAGE REFERENCE CHART

      Voltage Criteria
      Approx. 5 V Wire is not broken
      Approx. 10 or 0 V Wire is broken

      HINT:

      If there is approximately 10V, the wire may be faulty between the center of the wire and the wire and on the battery side. If there is no voltage, the wire may be faulty between the center of the wire and the wire end on the ground side.

      Fig 3: Checking Voltage Center Of Defogger Wire
      G04833939Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    4. Place the voltmeter's positive (+) lead against the defogger wire on the battery side.
    5. Place the voltmeter's negative (-) lead with the foil strip against the wire on the ground side.
    6. Slide the positive (+) lead from the battery side to the ground side.
    7. The point where the voltage drops from approximately 10 V to 0 V is the place where the defogger wire is broken.

      HINT:

      If the defogger wire is not broken, the voltmeter should indicate 0 V at the positive (+) end of the defogger wire but gradually increases to approximately 12 V as the meter probe moves to the other end.

  2. INSPECT FRONT WINDOW (DEICER WIRE) 
    1. Check the resistance of the deicer wire.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART

      Tester Connection Condition Specified Condition
      1 - 2 Always Below 1 Ω
      3 - 2 Always Below 1 Ω

      HINT:

      If the result is not as specified, replace the front window.

      Fig 4: Identifying Deicer Wire Connector Terminals
      G05243955Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002