2010 GMC Acadia Owner's Manual - Page 185

Lighting 6-5 Interior Lighting Instrument Panel Illumination Control D (Instrument Panel Brightness): The knob with this symbol on it is next to the exterior lamps control to the left of the steering wheel. Push the knob in all the way until it extends out and then turn the knob clockwise or counterclockwise to brighten or dim the lights. Push the knob back in when finished. The reading lamps, located on the headliner above the rearview mirror, can be turned on or off independent of the automatic courtesy lamps, when the doors are closed. Dome Lamp Override The dome lamp override button is next to the exterior lamps control. E (Dome Lamp Override): Press the button in and the dome lamps remain off when a door is opened. Press the button again to return it to the extended position so that the dome lamps come on when a door is opened. Dome Lamps The dome lamps are located in the overhead console and above the rear seat passengers. The dome lamps automatically come on when a door is opened, unless the dome lamp override button is pressed in. The lamps can also be turned on and off by turning the instrument panel brightness control clockwise to the farthest position. Reading Lamps Press the button near each lamp to turn them on or off. Courtesy Lamps The courtesy lamps automatically come on when a door is opened. The lamps can also be turned on manually by fully turning the instrument panel brightness control clockwise.