Chevrolet 2000 Tahoe Owner's Manual page 178

You can turn the outlets from side
and down to direct the flow of air. The left driver
and passenger outlets on vehicles equipped with air
conditioning have shut off knobs. Turn the knob to
the left to shut off air flow, to the right to allow air flow.
When you close an outlet, it will increase the flow of air
coming out of any outlets that are open. The center
outlet does not completely shut off airflow.
3-14
Your vehicle has air outlets
in the center and on the
sides of the instrument
panel and also may be
equipped on the headliner.
- -
to side or up
Ventilation Tips
D
Keep the hood and front air inlet free of ice, snow or
any other obstruction (such as leaves). The heater
and defroster will work far better, reducing the
chance of fogging the inside of your windows.
D
When you enter a vehicle in cold weather, turn the
blower fan all the way to the right for a few moments
before driving. This helps clear the intake ducts of
snow and moisture, and reduces the chance of
fogging the inside of your windows.
D
Keep the air path under the front seats clear of
objects. This helps air to circulate throughout
your vehicle.
D
The use of hood air deflectors may adversely
affect the performance of the heating and air
conditioning system.