GM Service Manual Online
For 1990-2009 cars only
(Instrument Panel Brightness): This feature controls the brightness of the instrument panel lights. The knob for this control is located next to the exterior lamps control. Push the knob in and release when it pops out. Turn the knob clockwise to increase the brightness of the instrument panel lights and counter clockwise to decrease the brightness. Turning the knob completely clockwise to the detent will turn on the courtesy lamps.