Chevrolet 2005 Silverado 1500 Pickup Owner's Manual page 192

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.
If you select recirculation while in defrost, defog or floor,
the light in the button will flash and then go out to let you
know that this is not allowed. This is normal and helps to
prevent fogging.
When the weather is cool or damp, operating the system
in recirculation for extended periods of time may cause
fogging of the vehicle's windows. To clear the fog, select
either defog or front defrost.
You may also notice that the A/C compressor will run
while in recirculation mode. This is normal and helps to
prevent fogging.
9 (Off): Press this button to turn off the entire climate
control system. Outside air will still enter the vehicle,
and will be directed to the floor. This direction can
be changed by pressing the mode button. The
temperature can also be adjusted using either
temperature knob. Press the up or down arrows on the
fan switch, the defrost button, the AUTO button, or
the air conditioning button to turn the system on when
it is off.
3-28
Display
If you press the MODE button to select an air delivery
mode, the display will change to show you the selected
air delivery mode. After ten seconds, the display will
change to show the driver temperature setting and the
selected mode.
If you press the up or down arrows on the fan switch,
the display will change to show the selected fan speed.
After ten seconds, the display will change to show
the driver temperature setting and the selected mode.
Whenever you press AUTO, the display will change
to show the following:
•
The current driver's set temperature and an arrow
for five seconds
•
The current passenger's set temperature setting
and an arrow for five seconds
•
The automatic air delivery mode and fan speed
If the driver's and passenger's temperature settings
are the same when AUTO is pressed, the temperature
setting and both arrows will be displayed for
five seconds along with the automatic air delivery
mode and fan speed. After the five second update,
the display will change to show the temperature setting,
both arrows and AUTO.