Rear Window Does Not Defog
WARNING: This page is about a different car, the 2002 Ford Focus. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition on. Locate defogger relay. See COMPONENT LOCATIONS . Press rear defogger switch. If defogger relay clicks, go to next step. If defogger relay does not click, go to step 7.
- Turn ignition off. Using an ohmmeter, check fuse F7 (40-amp). See COMPONENT LOCATIONS . If fuse is okay, go to next step. If fuse is blown, replace fuse. If fuse blows again, repair short to ground in Red wire and retest system operation.
- Turn ignition off. Disconnect defogger relay. Using voltmeter, measure voltage between Central Junction Box (CJB) defogger relay connector terminal No. 3 (Red wire) and ground. See Fig 1. If battery voltage is present, go to next step. If battery voltage is not present, repair open in Red wire and retest system operation.
- Using ohmmeter, check fuse F50 (7.5-amp). See COMPONENT LOCATIONS . If fuse is okay, go to next step. If fuse is blown, replace fuse. If fuse blows again, repair short to ground in Green/Blue wire and retest system operation.
- Reconnect defogger relay. Disconnect rear window defogger grid wire connector on left side of rear window. Turn ignition on. Activate rear window defogger. Using a voltmeter, measure voltage between Green/Blue wire at rear window defogger wire connector and ground. If battery voltage is present, go to next step. If battery voltage is not present, repair open or short in Green/Blue wire and retest system operation.
- Turn ignition off. Reconnect rear window defogger grid wire connector. Disconnect rear window defogger grid wire connector on right side of rear window. Using an ohmmeter, measure resistance between Black wire at rear window defogger grid wire connector and ground. If resistance is less than 5 ohms, replace rear window. If resistance is greater than 5 ohms, repair open in Black wire and retest system operation.
- Perform DEFOGGER RELAY TEST under COMPONENT TESTS. If defogger relay tests okay, go to next step. If defogger relay does not test okay, replace defogger relay and retest system operation.
- Turn ignition on. Using a voltmeter, measure voltage between CJB defogger relay connector terminal No. 1 (Green/Yellow wire) and ground. See Fig 1. If battery voltage is present, go to next step. If battery voltage is not present, repair open in Green/Yellow wire and retest system operation.
- Using ohmmeter, check fuse F45 (7.5-amp). See COMPONENT LOCATIONS . If fuse is okay, go to next step. If fuse is blown, replace fuse. If fuse blows again, repair short to ground in Green/Red wire and retest system operation.
- Disconnect rear defogger switch harness connector C380. Measure voltage at C380 terminal No. 10 (Green/Red wire). See Fig 2. If battery voltage is present, go to next step. If battery voltage is not present, repair open in Green/Red wire and test system operation.
- Disconnect rear defogger switch harness C380. Perform REAR DEFOGGER SWITCH TEST . If rear defogger switch tests okay, go to next step. If rear defogger switch does not test okay, replace rear defogger switch and retest system operation.
- Turn ignition OFF. Disconnect GEM connector C105. Measure resistance between connector C105 terminal No. 15 and rear window defogger relay terminal No. 2 (Black/Orange wire). See Fig 3 and Fig 1 . If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open in Black/Orange wire.
- Reconnect GEM connector C105. Disconnect GEM connector C104. Measure resistance between connector C104 terminal No. 20 and rear window defogger switch connector C380 (Black/Green wire). See Fig 3 and Fig 2 . If resistance is less than 5 ohms, system wiring okay, verify customer concern. If resistance is greater than 5 ohms, repair open Black/Green wire and test system operation.