Skip the auto shop - Our mechanics make house calls

Q: How Does the Power Mirror Switch Work?

asked by on

How does the power mirror switch work?

A conventional power mirror switch is essentially two rocker switches built into a single housing. Each rocker switch is connected to two wires that are connected to a reversible DC (direct current) motor inside the rear view mirror on either door. Each rear view mirror has two DC motors. One DC motor operates the up/down function while the other DC motor operates the left/right function.

Both of the rocker switches inside the power mirror switch are constantly connected to the vehicle’s electrical ground circuit with the switch at rest. When you press the switch in any mirror direction, the switch connects one of the two wires of a motor to power (12 volts DC) while keeping the other circuit connected to ground. Electricity then flows through the switch to the DC motor and the mirror head moves in the intended direction. If you press the same switch to the opposite direction, you are reversing the electricity to the mirror motor and the mirror moves in the opposite direction.

For example, let’s adjust the driver’s side rear view mirror. Push the mirror switch to the right, which moves the mirror inward (toward the vehicle). One of the two wires of the L/R mirror motor, wire A, receives power while the other wire, wire B, is connected to ground. This causes the mirror to move inward. Likewise, if you push the mirror switch to the left. Wire A is now connected to ground and wire B is connected to power, causing the L/R mirror motor to move the mirror outward. The same concept occurs when you adjust the mirror up and down.

Many power mirror switches have a neutral or center position, which locks the mirrors in place and prevents any mirror adjustment from occurring.

Newer vehicles utilize control modules (computers) to operate the power mirrors. The power mirror switch is then used to provide a simple command signal to the control module indicating the desired direction. The switch is not directly connected to the mirror motors in this case.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Air conditioning blockage pressure - 1988 Mercedes-Benz 300TE

Hey there. The condenser is blocked or the expansion valve is stuck causing the problem. Make sure when testing you have proper air flow across the condenser. If the fan clutch is not working good then the pressures will be...

Q: Is There a Way to Reduce Glare From Car Mirrors?

When it comes to the interior or rear view mirror, the quickest way to reduce glare is to use the tab lever under the mirror to rotate the angle of the mirror which changes the angle of the reflected light...

Q: How do I lock the power windows?

The power windows can be locked so that children are unable to operate them. To lock the power windows, press the power window lock switch, which is located in front of the driver’s power window switches. Press this button a...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...