Electric Mirror Repair: Adjusting the Voltage

Lead Image
  • 2-4 hours
  • Intermediate
  • 5-50
What You'll Need
Electrical test light
Piece of electrical wire (about 2 to 3 feet in lenghth)
Car service manual
Electrical tape or wire caps
Wire cutters

If you are having problems with your car's electric mirror, it could be a result of a severed or shorted electrical connection or other voltage related problems. The problem could be a faulty fuse, or a short in the wiring leading to the mirror from the fuse panel. Fortunately, troubleshooting or adjusting electrical voltage problems with your car's electric mirror is not that difficult, and this simple how-to guide will show you how to make adjustments and corrections to get your electric mirror working again.

Step 1 - Switch Ignition to 'ACC' Position

Place the key in your car's ignition, and turn the switch to the 'ACC' position. Do not start the car, but rather simply ensure that devices in your car are receiving power. When your car's ignition switch is in this position, the mirrors should be able to be operated as they normally would while you are driving.

Step 2 - Check the Fuse

Refer to your car owners manual or the fuse digram on the fuse box cover to see which fuse contis used for electrical mirrors in your vehicle. Then, remove the fuse and inspect it. If the small metal filament in the fuse appears to be broken or corroded, replace the fuse and see if that fixes the voltage problems for your electric mirrors.

Step 3 - Inspect the Electrical Wiring Between Mirror and Fuse Panel

If the problems with your car's electrical mirror are not related to a bad fuse, you will then need to inspect the wiring between the electrical mirror and the fuse panel. If you are having problems with a driver or passenger side electrical mirror, you'll need to remove the door panel on the side of the faulty mirror. Once you have gained access to the wiring for the electrical mirror, inspect the entire length of the wiring for any breaks in the wiring that could indicate a short that will prevent the necessary voltage from being passed from your car's battery to the electrical mirror.

If you do find breaks in the wiring, you can attempt to splice the wiring with electrical tape or wire caps and see if this corrects the voltage issues with your electrical mirrors. Even if you do not notice any visible breaks in the wiring, you should use the multimeter to test the continuity of the wiring.

Step 4 - Check the Controller

Unplug the control switch for the faulty electrical mirror and use a multimeter to test for continuity. If there are continuity problems with the control switch, purchase a new one from the dealer and replace it. You can also use a piece of electrical wire to assist you in testing the control switch. Once you remove the switch from the mounting panel, leave the wiring connected and attach one end of the piece of electrical wire to the ground position on the control switch and the other end to a grounded piece of metal on your vehicle. Then attempt to use the mirror. If the mirror works, you will need to replace the ground wire used with the control switch.