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 control, located at the bottom of the mirror, lessens glare from the headlamps behind your vehicle when in the night position. Turn the control to the right for the night position and to the left for the day position.

Two buttons under the rearview mirror control map lamps. Push each button to turn each map lamp on or off.