GMC SIERRA 1997 Manual page 108

Crew Cab
If you have the optional power windows, the controls
are on each of the side doors.
The driver's door has a switch for the passenger
windows as well. Your power windows will work when
the ignition has been turned to ACCESSORY or RUN.
Press the rear of the switch with the power window
symbol on it to lower the window.
Press the front of the switch with the power window
symbol on it to raise the window.
The driver's window also has an express down feature
that allows the window to be lowered without holding
the switch. Press and hold the side of the window switch
marked AUTO for one second to activate the express
down mode. The express down mode can be canceled at
any time by pressing the opposite side of the switch. To
open the window partway, lightly tap the switch until the
window is at the desired position.
Lockout Switch (Crew Cab)
If you have a Crew Cab and power windows, the power
window switch has a lockout feature. This feature
prevents the rear windows from operating when the
front driver's side switch is in LOCK. The windows can
still be operated using the driver's window switch.
When the switch is moved to NORM, the rear power
windows will operate again.
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