Rear Defogger Switch Indicator Inoperative (Rear Window Defogger Operates)
- Check fuse No. 11 (10-amp) located in junction block. If fuse is blown, go to next step. If fuse is okay, go to step 3.
- Turn ignition off. Remove fuse No. 11. On vehicles equipped with manual air conditioning, disconnect A/C-heater control panel connector. On vehicles equipped with automatic air conditioning, disconnect Automatic Zone Control (AZC) module connector. On vehicles equipped with manual air conditioning, using DVOM, measure resistance between A/C-heater control panel connector C1 terminal No. 5 (Black/White wire) and ground. See Figure. On vehicles equipped with automatic air conditioning, using DVOM, measure resistance between AZC module connector C1 terminal No. 14 (Black/White wire) and ground. See Figure. On all models, if resistance is greater than 5 ohms, replace fuse. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If resistance is less than 5 ohms, repair short to ground in Black/White wire. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
- Turn ignition off. Disconnect Automatic Zone Control (AZC) module or A/C-heater control panel connectors. Access junction block and remove rear window defogger relay. Ensure fuse No. 11 is installed in junction block. On vehicles equipped with manual air conditioning, using DVOM, measure resistance between A/C-heater control panel connector C1 terminal No. 4 (Black/White wire) and rear window defogger relay socket No. 87. On vehicles equipped with automatic air conditioning, using DVOM, measure resistance between AZC module connector C1 terminal No. 6 (Black/White wire) and rear window defogger relay socket No. 87. On all models, if resistance is less than 5 ohms, go to next step. On all models, if resistance is greater than 5 ohms, repair open in Black/White wire between rear window defogger relay and AZC module or A/C-heater control panel. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
- Replace AZC module or A/C-heater control panel. See appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.