GMC 2006 Sierra - Manual (Page 196)

Auxiliary Roof Mounted Lamp
If your vehicle has this feature, this button includes
wiring provisions for a dealer or a qualified service
center to install an auxiliary roof lamp.
This button is located
on the center of the
instrument panel near
the climate controls.
When the wiring is connected to an auxiliary roof
mounted lamp, pressing the button will activate the lamp
and illuminate an indicator light near the button. Pressing
the button again will turn off the roof mounted lamp.
If your vehicle has this button, your vehicle may have the
snow plow prep package. For further information see
Adding a Snow Plow or Similar Equipment on page 4-54.
Instrument Panel Brightness
D
(Instrument Panel Brightness): This feature
controls the brightness of the instrument panel lights.
The thumbwheel for this feature is located next to
the headlamp control.
Turn the thumbwheel up to adjust the instrument panel
lights. Turn the thumbwheel up to return the radio display
to full brightness when the headlamps or parking lamps
are on. To turn on the dome lamps, turn the thumbwheel
all the way up.
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 exterior lamps control,
all the way up. In this position, the dome lamps will
remain on whether a door is opened or closed.
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