GM Service Manual Online
For 1990-2009 cars only

To block out glare, you can swing down the top and bottom visors. You can also swing the bottom visor from side-to-side. The visors may also have an extension that can be pulled out for additional glare protection.

Illuminated Visor Vanity Mirrors

Your vehicle may have this feature. If it does, pull the sun visor down and lift the mirror cover to turn on the lamps. There is a slide switch to adjust the intensity of the lamps.