Rear Window Defogger Function Test

With climate control; Before troubleshooting the rear window circuit, perform multiplex integrated control system troubleshooting test mode A. NOTE:

- Be careful not to scratch or damage the defogger wires with the tester probe.
- Before testing, check the No. 14 (40 A) and No.2 (30 A) fuses in the under-hood fuse/relay box and No. 30 (7.5 A) fuse in the under-dash fuse/relay box.

1. Check for voltage between the positive terminal (A) and body ground with the ignition switch and defogger switch ON.
   There should be battery voltage.
   - If there is no voltage, check for:

   - | Faulty defogger relay.
   - | Faulty window antenna coil.
   - | Faulty climate control unit (or heater control panel)
   - | An open in the BLK/YEL wire to the positive terminal.

   - If there is voltage, go to Step 2 .

1. Disconnect the negative terminal (B) from the rear window defogger.

1. Check for continuity between the negative terminal (B) and body ground.
   If there is no continuity, check for: An open in the BLK/YEL wire and ground. If there is continuity, go to Step 4 .

1. Touch the voltmeter positive probe to the quarter points (1), (2), (3) on each defogger wire, and the negative probe to the negative terminal.
   - If the voltage is as specified, the defogger wire up to that point is OK.
   - If the voltage is not as specified, repair the defogger wire.

   - | If it is more than specified at one of the points, there is a break in the negative half of the wire.
   - | If it is less than specified at one of the points, there is a break in the negative half of the wire.

1. Reconnect the negative terminal to the rear window defogger.

1. Turn on the ignition switch ON and the rear defogger ON.