Defogging And Defrosting - GMC 1999 Envoy Owner's Manual

Air Conditioning
On hot days, open the windows long enough to let hot
inside air escape. This reduces the time it takes for your
vehicle to cool down. Then keep your windows closed
for the air conditioner to work its best.
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For quick cool down on very hot days, the A/C button
should be enabled and the OUTSIDE AIR button should
not be active.
On cool but sunny days, use BI
warm air to the floor and cooler air to the instrument
panel outlets.
When the air conditioner is on, you may sometimes
notice slight changes in your vehicle's engine speed and
power. This is normal because the system is designed to
cycle the compressor on and off to keep the
desired temperature.
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LEVEL A/C to deliver
Heating
The heater works best if you keep your windows closed
while using it. On cold days, use HEATER with the
temperature knob turned toward the red area. BLEND is
useful in cool weather when you have fog or ice on the
windshield or side windows.
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.

Defogging and Defrosting

On cool, humid days, use BLEND to keep the
windshield and side windows clear.
Use DEFROST to remove fog or ice from the
windshield quickly in extreme humid or cold conditions.
Turn the temperature knob toward the red area and
move the fan control toward the red area.
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