GM Service Manual Online
For 1990-2009 cars only

When you are sitting in a comfortable driving position, adjust the mirror so you can see clearly behind your vehicle. Grip the mirror in the center to move it up or down and side to side. The day/night adjustment allows you to adjust the mirror to avoid glare from the lamps behind you. Push the tab forward for daytime use and pull it for nighttime use.

The mirror may have lights located on the bottom of the mirror. Press the button next to each light to turn it on or off.