Comfort Control System; Flow-Through Ventilation System - GMC 1999 Sierra 1500 Pickup Owner's Manual

Comfort Controls & Audio Systems
Comfort Control System
Flow-Through Ventilation System
K2302
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, through the vehicle and out the rear air exhaust
valves. Outside air will also enter the vehicle when the heater or the air
conditioning fan is running.
Ventilation Tips
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.
When you enter a vehicle in cold weather, turn the blower fan to HI for
a few moments before driving off. This helps clear the intake ducts
of
snow and moisture, and reduces the chance of fogging the inside of
your windows.
Keep the air path under the front seats clear of objects. This helps air
to circulate throughout your vehicle.
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