Air Conditioning - GMC C series 2002 Owner's Manual

OFF: Press this button to turn the air
conditioning/heating system off. Pressing OFF will
erase the present mode of operation from the system's
memory. Outside air will still come out of the heater
outlet whenever the vehicle is moving forward.
If the OFF button is pressed, you must press A/C,
MAX or one of the BLEND buttons to turn the
system back on.

Air Conditioning

When you first turn on your vehicle's air conditioning,
open the windows long enough to clear the vehicle of
hot air, then close them. Using the MAX button can
also help. See "MAX" earlier in this section for
more information.
For normal cooling on hot days, use A/C with the
temperature selector toward C.
When you press the A/C button to turn the air
conditioner off, the system will operate in the vent
mode. When you turn the air conditioner back on, the
system will operate in the mode you last selected unless
the OFF button was pressed.
If your air conditioner develops high system pressure,
it will automatically go into the MAX mode and REC
will light on your display. The A/C system will remain
in the MAX mode, even if you press the MAX button,
until system pressure returns to a normal level.
Heating
On cold days, use floor with the temperature selector all
the way toward H. When the inside of the vehicle has
reached a comfortable temperature, maintain it by using
the temperature selector bar.
If your vehicle is equipped with a diesel engine, and the
engine has been idling for a long time when it's cold
outside, your heater may blow out cool air. This is
normal. When you increase the engine speed under load,
your heater should blow out warmer air. If it doesn't,
your coolant level may be low. See "Engine Coolant" in
the Index to check your coolant level.
While idling your diesel engine, you can use the MAX
button to recirculate the air in the cab to help maintain
interior heat. This will preserve engine coolant
temperature and cab heat when idling cannot be
avoided.
Using the MAX button while driving is not
recommended because interior window fogging
can result.
3-5