GMC Sierra Classic 2007 Owner's Manual page 236

Manual Operation
You may manually adjust the air delivery mode or
fan speed.
w9x
(Fan): The switch with the fan symbol
allows you to manually adjust the fan speed. Press
the up arrow to increase fan speed and the
down arrow to decrease fan speed.
Pressing this button when the system is off will
turn the system on.
C
(Mode): Press this button to manually change
the direction of the airflow in your vehicle;
repeatedly press the button until the desired mode
appears on the display.
If you press the mode button to select an air
delivery mode, the display will change to show you
the selected air mode delivery. The display will then
show the current status of the system. When the
system is turned off, the display will go blank after
displaying the current status of the system.
H
(Panel): This mode directs air to the
instrument panel outlets.
236
)
(Bi-Level): This mode directs warmer air to
the floor and cooler air to the instrument
panel outlets.
6
(Floor): This mode directs air to the
floor outlets.
-
(Defog): See "Defogging and Defrosting" later
in this section.
@
(Recirculation): Press this button to limit the
amount of outside air entering your vehicle.
The light on the recirculation button will glow. This
is helpful when you are trying to limit odors
entering your vehicle and for maximum air
conditioning performance in hot weather. Press
this button again to allow outside air to enter
the vehicle. The light on the recirculation button
will go off.
Pressing this button also cancels the auto
recirculation feature. To resume the auto
recirculation function, press the AUTO button.
Each time the vehicle is started, the system will
revert to the auto recirculation function.