Mirrors: Testing and Inspection

AUTOMATIC DAY/NIGHT MIRROR

For complete circuit diagrams, refer to the appropriate wiring information.

1. Check the fused ignition switch output (run/start) fuse in the junction block. If OK, go to STEP 2. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.

2. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output (run/start) fuse in the junction block. If OK, go to STEP 3. If not OK, repair the open fused ignition switch output (run/start) circuit to the ignition switch as required.

3. Disconnect the overhead wire harness connector from the automatic day/night mirror connector receptacle. Check for battery voltage at the fused ignition switch output (run/start) circuit cavity of the overhead wire harness connector for the automatic day/night mirror. If OK, go to STEP 4. If not OK, repair the open fused ignition switch output (run/start) circuit to the fuse in the junction block as required.

4. Turn the ignition switch to the Off position. Check for continuity between the ground circuit cavity of the overhead wire harness connector for the automatic day/night mirror and a good ground. There should be continuity. If OK, go to STEP 5. If not OK, repair the open ground circuit to ground as required.

5. Turn the ignition switch to the On position. Set the parking brake. Place the transmission gear selector lever in the Reverse position. Check for battery voltage at the backup lamp switch output circuit cavity of the overhead wire harness connector for the automatic day/night mirror. If OK, reconnect the overhead wire harness connector to the automatic day/night mirror connector receptacle and go to STEP 6. If not OK, repair the open backup lamp switch output circuit as required.





6. Place the transmission gear selector lever in the Neutral position. Place the automatic day/night mirror switch (2) in the Auto (LED (1) next to the switch is lighted) position. Cover the forward facing ambient photocell sensor to keep out any ambient light.

NOTE: The ambient photocell sensor must be covered completely, so that no light reaches the sensor. Use a finger pressed tightly against the sensor, or cover the sensor completely with electrical tape.

7. Shine a light into the rearward facing headlamp photocell sensor (3). The automatic day/night mirror should darken. If OK, go to STEP 8. If not OK, replace the faulty automatic day/night mirror unit.

8. With the mirror darkened, place the transmission gear selector lever in the Reverse position. The automatic day/night mirror should return to its normal reflectance. If not OK, replace the faulty automatic day/night mirror unit.