2001 GMC Sierra 1500 Pickup Owner's Manual - Page 145

Front Reading Lamps (If Equipped) If your vehicle has reading lamps, press the button located next to the lamp to turn the lamp on. The lamps can be adjusted to point in the direction you want. Dome Lamps The dome lamps will come on when you open a door. You can also turn the dome lamps on by turning the thumbwheel, located next to the parking/headlamps knob, all the way up. In this position, the dome lamps will remain on whether the doors are opened or closed. You can use the DOME OVERRIDE button, located below the parking/headlamp knob, to set the dome lamps to come on automatically when the doors are opened, or remain off. To turn the lamps off, press the button into the "in" position. With the button in this position, the dome lamps will remain off when the doors are open. To return the lamps to automatic operation, press the button again and return it to the "out" position. With the button in this position, the dome lamps will come on when you open a door. Press the button again to turn the lamp off. 2-62