How to Troubleshoot an Electric Rear View Mirror

Most car electric rear view mirrors come equipped with two small, direct current, reversible motors. A small joy stick or control switch is used to operate the mechanism that moves the mirror into different angles. Even though internal repairs are not usually possible, there are several trouble spots that may cause a power mirror to fail. This problem spots are easy to locate and repair. The steps outlined next will guide you through to find any problem with your mirror or mirrors and make the necessary repairs. If you have a very basic knowledge of electricity or want to learn basic troubleshooting procedures, lets get started.

Instructions

1

Turn the ignition switch on but do not start the engine. Operate the rear view mirror control switch and listen for the motors running. If you can hear the motors, there is a problem with the drive mechanism inside the mirror housing. Most mirror assemblies have to be replaced as a unit. Check with your local dealer. If you do not hear the motors running, go to the next step.

2

Check the main fuse for the electric mirror circuit if both mirrors fail to operate.

3

Dismount the control switch from the panel without disconnecting any wires.

4

Turn the ignition on and check for incoming voltage at the control switch using a test light. If there is no voltage, look for an open or short in the wire between the switch and the fuse panel.

5

Unplug the switch and check it for continuity in its different positions using a multimeter. If there is no continuity, replace the switch.

6

Check the control switch ground connection using a jumper wire. With the control switch off its mounting panel and wires connected, hook one end of the jumper wire to the switch ground connector and the other end to a good ground on the vehicle. Turn on the ignition switch and operate the mirror. If the mirror works, locate the open or short along the control switch ground wire.

7

Check for voltage at the wires connecting to the mirror assembly. Remove the mirror and take out the mirror assembly from its housing if necessary, but leave the wires connected. Turn on the ignition switch. Using a test light, check for voltage at the wires connecting to the motors as you operate the control switch. If there is no voltage, inspect the wires going to the motors for a possible open or short. If voltage is present, replace the mirror assembly.