Older vehicles and cars with base trim levels may have manual mirror adjustment. The most basic method is adjusting the mirror glass directly on the mirror assembly, or it can be adjusted by a manual cable toggle control. While manual mirrors are not totally extinct, they are becoming extremely uncommon.
Virtually all new vehicles are equipped with power mirror adjustment. The workings of a power mirror system include:
- Side mirror power adjustment motors
- Electrical connectors
- Mirror switch with directional control
- Fused power mirror circuit
If any one part of the system is faulty, the whole system won’t work.
How does the mirror control switch work?
Only the side mirrors are controlled by the power mirror switch. The inside rearview mirror is manual adjustment. The power mirror switch has three positions: left, off, and right. When the switch is in the center position, neither mirror will be adjusted if the button is pressed. This is to ensure that the mirrors don’t move if the directional control button is accidentally hit.
The directional control button has four directions that the mirror motor can move: up, down, right, and left. If the switch is moved to either the left or right side, that side mirror motor circuit is powered at the switch. When you press the directional control button on the switch, the mirror motor inside the mirror housing will pivot the mirror glass to the selected direction. When you release the button, the mirror stops moving.
The mirror motor has a limited amount of travel that is allowed to prevent damage to the mirror glass. Once the travel limit is reached, the motor will continue to click and bind until the directional control button is released. Continuing to press the button when at its limit will cause the mirror motor to burn out eventually, and it will cease to operate until it is replaced.
Making sure your mirrors are adjusted for proper rear and side-view visibility is extremely important to safely operating your car. You need to be able to see the traffic beside and behind you to make informed decisions about your driving. Check your mirror adjustment every time you start your car to make sure they are positioned properly for you.
This article originally appeared on YourMechanic.com as How Does the Side Mirror Control Switch Work? and was authored by Jason Unrau.