Defogger Wire
WARNING: This page is about a different car, the 2003 Lexus IS 300 and 2002 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
When cleaning the glass, use a soft dry cloth and wipe the glass in the direction of the wire. Take care not to damage the wires. Do not use detergents or glass cleaners with abrasive ingredients.
NOTE:
When measuring the voltage, wrap a piece of tin foil around the tip of the negative probe and press the foil against the wire with your finger. See Fig 1.
- Turn the ignition switch and defogger switch ON.
- Inspect the voltage at the center of each heat wire. See Fig 2. See INSPECTING DEFOGGER WIRE VOLTAGE table.INSPECTING DEFOGGER WIRE VOLTAGE
Voltage Criteria Approximately 5 Volts OK (No Break In Wire) Approximately 10 Volts Or 0 Volt (1) Broken Wire (1) If there is approximately 10 Volts, the wire is broken between the center of the wire and the positive (+) end. If there is no voltage, the wire is broken between the center of the wire and ground. - Place the voltmeter positive (+) lead against the defogger wire on the battery side. Place the voltmeter negative (-) lead with the foil strip against the wire on the ground side. Slide the positive (+) lead from battery to ground side. The point where the voltmeter deflects from several volts to 0 volt is the place where the defogger wire is broken. If the heat wire is not broken, the voltmeter indicates 0 volt at the positive (+) end of the heat wire but gradually increases to about 12 volts as the meter probe moves to the other end.