GMC 2007 Sierra - Manual (Page 228)

Cargo Lamp
The cargo lamp button
is located on the left
side of the instrument
panel. Press the
button to turn the cargo
lamp on or off.
An indicator light on the instrument panel cluster
will come on when the cargo lamp is turned
on, and the ignition key is turned to RUN.
Accessory Power Outlet(s)
Accessory power outlets can be used to connect
auxiliary electrical equipment, such as a cellular
telephone or CB radio. The outlet can accept
electrical equipment up to a maximum of
20 amperes.
Your vehicle may have two accessory power
outlets, or may have one accessory power outlet
located near the cigarette lighter, if the vehicle
has one. The cigarette lighter is designed to fit only
in the receptacle to the right of the accessory
power outlet.
To use an outlet, remove the protective cap.
When not in use, always cover the outlet with the
protective cap. The accessory power outlet is
operational at all times.
Notice: If electrical devices are left plugged
into a power outlet, the battery may drain
causing your vehicle not to start or damage to
the battery. This would not be covered by
the warranty. Always unplug all electrical
devices when turning off your vehicle.
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