REAR WINDOW DEFOGGER Troubleshooting Problem | Possible cause | Remedy | Page Rear window defogger does not work | Circuit breaker OFF | Reset breaker and check for short | BE-4 | GAUGE fuse blown | Replace fuse and check for short | BE-4 | Defogger switch faulty | Check switch | BE-47 | Defogger relay faulty | Check relay | BE-47 | Defogger wire broken | Check wires | BE-48 | Wiring and ground faulty | Repair as necessary | Rear Window Defogger Switch INSPECTION OF DEFOGGER SWITCH INSPECT SWITCH OPERATION (a) Connect the positive (+) lead from the battery to terminal 3 and the negative (−) lead to terminal 4. Connect terminals 3 and 5 through a 3.4W test bulb. (b) Push the defogger switch on. Check that the bulb lights for 12 to 18 minutes, then the bulb goes out. If operation is not as specified, replace the switch. Rear Window Defogger Relay (See Taillight Control Relay on page BE-22) Rear Window Defogger Wires CAUTIONS: • 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. • When measuring voltage, wind a piece of tin foil around the tip of the negative probe and press the foil against the wire with your finger as shown.