Chevrolet 2008 Avalanche Owner's Manual page 206

2. Set the driver's and passenger's temperature.
To find your comfort setting, start with a 74°F
(23°C) temperature setting and allow about
20 minutes for the system to regulate. Use the
driver's or passenger's temperature buttons to adjust
the temperature setting as necessary. If you choose
the temperature setting of 60°F (15°C), the system
will remain at the maximum cooling setting. If you
choose the temperature setting of 90°F (32°C), the
system will remain at the maximum heat setting.
Choosing either maximum setting will not cause the
vehicle to heat or cool any faster.
Be careful not to cover the solar sensor located on the
top of the instrument panel near the windshield. This
sensor regulates air temperature based on sun load and
also turns on your headlamps. For more information
on the solar sensor, see "Sensors" later in this section.
To avoid blowing cold air in cold weather, the system
will delay turning on the fan until warm air is available.
The length of delay depends on the engine coolant
temperature. Pressing the fan switch will override this
delay and change the fan to a selected speed.
3-26
O (On/Off): Press this button to turn off the 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. Recirculation can be
selected once you have selected vent or bi-level mode.
The temperature can also be adjusted using either
temperature button. If you adjust the air delivery mode or
temperature settings with the system off, the display will
illuminate briefly to show you the settings and then return
off. Press the on/off button or the up down arrows on the
fan switch, the defrost button, AUTO button, or the air
conditioning button to turn the system on when it is off.