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: A conventional power mirror switch is essen...

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: Car turns off

The problem sounds like your alternator has stopped charging the car. This will cause the car to have weak electronics like what you are experiencing. Have the charging system double checked, and if verified as the fault, replace the bad...

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: Brake lights are not working.

Check the turn signal switch and see if its sticking in place. A bad turn-signal switch may interrupt the brake light circuit and cause the brake lights to not function. Also a broken wire to or from the brake light...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.