DTC B1347 - Defogger Relay Output Circuit Fault
WARNING: This page is about a different car, the 1997 Mercury Sable and 1997 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
- Check For Power At Window Grid
Turn ignition on. Press rear defogger switch. Measure voltage between defogger grid connector (Brown/Light Blue wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, go to step 4). - Check Defogger Relay For Short
Turn ignition off. Remove rear defogger relay. Measure resistance between rear defogger relay connector terminal No. 85 and ground. See Fig 1. If resistance is less than 10 k/ohms, go to next step. If resistance is greater than 10 k/ohms, replace defogger relay. - Check Fuse Junction Panel
Unplug 19-pin harness connector from Generic Electronic Module (GEM), located in interior fuse panel. Measure resistance between rear defogger relay connector terminal No. 85 and ground. See Fig 1. If resistance is less than 10 k/ohms, replace interior fuse pan el. If resistance is greater than 10 k/ohms, replace GEM. Restore electrical connections and repeat self-diagnostics. - Check For Power At Defogger Relay
Turn ignition off. Remove rear defogger relay. Turn ignition on. Measure voltage between rear defogger relay connector terminal No. 85 and ground. See Fig 1. If battery voltage exists, go to step 6). If battery voltage does not exist, go to next step. - Check Brake Shift Interlock Operation
Brake Shift interlock is powered by same fuse as defogger relay (fuse No. 5). Turn ignition on. Press brake pedal. Shift transmission from Park to any other gear. If gear selector shifts out of Park, replace interior fuse panel. If gear selector does not shift out of Park, check fuse No. 5 is okay and service if necessary. If fuse is okay, repair Red/Light Blue wire between ignition switch and fuse panel. - Check Voltage At GEM
Disconnect 16-cavity connector from GEM. Turn ignition on. Check for battery voltage at pin No. 14 (Red/Yellow wire). If battery voltage exists, replace GEM. If battery voltage does not exist, go to next step. - Check Fuse Panel For Open Circuit
Turn ignition off. Remove rear defogger relay. Measure resistance between rear defogger relay pins No. 30 and 87. See Fig 1. Resistance should be 10 k/ohms or greater. Apply battery power and ground to defogger relay terminals No. 85 and 86. Measure resistance between terminals No. 30 and 87. Resistance should be less than 5 ohms. If resistance measurements are as specified, replace fuse junction panel and repeat self-diagnostics. If resistance measurements are not as specified, replace rear defogger relay and repeat self-diagnostics.