GMC 2000 Automobile User Manual


 
3-6
Heating
On cold days, use HEATER with the temperature knob
in the red area. Outside air will be brought in through
the floor outlets. The heater works best if you keep your
windows closed while using it.
If you use the optional engine coolant heater before
starting your engine, your heating system will produce
warmer air faster to heat the passenger compartment in
cold weather. See “Engine Coolant Heater” in the Index.
Defrosting
Use DEFROST to remove fog or ice from the
windshield quickly in extremely cold conditions. The
temperature knob should be in the red area and the fan
control toward high. The air conditioning compressor
may operate in this setting to dehumidify the air.
The BLEND setting is useful for cold weather with a
large number of passengers or very humid conditions to
help keep the windshield clear.
Ventilation System
For mild outside temperatures when little heating or
cooling is needed, use VENT to direct outside air
through your vehicle. Air will flow through the
instrument panel vents.
Your vehicle’s flow
-through ventilation system supplies
outside air to the inside of your vehicle when it is
moving. With the side windows closed, air will flow into
the front air inlet grilles at the base of the windshield,
through the vehicle and out the rear air exhaust valve.
Outside air will also enter the vehicle when the heater or
the air conditioning fan is running.