Test B: Auto Dimming Feature Malfunctioning
- Press MIRROR button on inside mirror and hold for 3 second. If mirror does not darken, go to next step. If mirror darkens, go to step 7).
- Disconnect inside mirror harness connector. Turn ignition switch to RUN position. Measure voltage at terminal No. 7 (Purple/Orange wire) at inside mirror harness connector. See Fig 1
. If battery voltage does not exist, go to next step. If battery voltage exists, go to step 5).
- Remove fuse No. 5 (15-amp) from instrument panel fuse box. If fuse is okay, go to next step. If fuse is blown, repair short to ground in Purple/Orange wire or power distribution circuit. See appropriate POWER DISTRIBUTION wiring diagram in SYSTEM WIRING DIAGRAMS article in the WIRING DIAGRAMS section.
- Ensure ignition switch is in RUN position. Measure voltage at input side of fuse No. 5. If battery voltage exists, repair open in Purple/Orange wire. If battery voltage does not exist, repair power distribution. See appropriate POWER DISTRIBUTION wiring diagram in SYSTEM WIRING DIAGRAMS article in the WIRING DIAGRAMS section.
- Turn ignition switch to LOCK position. Measure resistance between ground and terminal No. 6 (Black wire) at inside mirror harness connector. If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open in black wire.
- Turn ignition switch to RUN position. Measure voltage at terminal No. 5 (Black/Pink wire) at inside mirror harness connector. Battery voltage should exists when transmission is in Reverse and battery voltage should not exist with transmission in any other gear. If voltage is as specified, connect inside mirror harness connector and go to next step. If voltage is not as specified, go to step 8).
- Ensure ignition switch is in RUN position and transmission is in Park. Cover light sensor or back of inside mirror and shine a flashlight on light sensor on mirror side of inside mirror. If mirror darkens, system is okay at this time. If mirror does not darken, replace inside mirror assembly.
- Disconnect Transmission Range (TR) sensor harness connector locate on side of transmission. Measure resistance in Black/Pink wire between terminal No. 11 at TR sensor harness connector and terminal No. 5 at inside mirror harness connector. See Fig 2
. If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open in Black/Pink wire.
- Remove fuse No. 5 (15-amp) from instrument panel fuse box. Measure resistance in Purple/Orange wire between output side of fuse No. 5 and terminal No. 9 at TR sensor harness connector. If resistance is greater than 5 ohms, repair open in Purple/Orange wire. If resistance is 5 ohms or less, adjust and/or replace TR sensor as necessary.
Courtesy of FORD MOTOR CO.
Courtesy of FORD MOTOR CO.