Diesel Data: Automotive Repair

Window Defogger System (for Automatic Air Conditioning System)








WINDOW / GLASS: WINDOW DEFOGGER SYSTEM (for Automatic Air Conditioning System): ON-VEHICLE INSPECTION

ON-VEHICLE INSPECTION

1. CHECK REAR WINDOW DEFOGGER SYSTEM OPERATION
(a) When the ignition switch is turned to ON and the defogger switch is pressed, check that the rear window defogger operates.
HINT: After 15 minutes, check that the defogger automatically turns off.

2. INSPECT BACK WINDOW (DEFOGGER WIRE)
NOTICE:
- 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.
- When measuring voltage, wrap a piece of tin foil around the tip of the negative tester probe and press the foil against the wire with your finger, as shown in the illustration.





(a) Turn the ignition switch to ON.
(b) Turn the defogger switch on.





(c) Check the voltage at the center of each defogger wire, as shown in the illustration.
Standard Voltage:





HINT: If there is approximately 10 V, the wire may be faulty between the center of the wire and the wire end 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.





(d) Place a voltmeter positive (+) lead against the defogger wire on the battery side.
(e) Place a voltmeter negative (-) lead with the foil strip against the wire on the ground side.
(f) Slide the positive (+) lead from the battery side to the ground side.
(g) 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 increase to approximately 12 V as the meter probe moves to the other end.