GMC chervolet camaro 1999 Service Manual page 212

HVAC
Air Distribution System Description
Vacuum regulates sir flow through the system.
Depending on the mode selected, the mode valves
mix and direct either cooled, heated, or outside
air through the air ducts. The various modes of
operation are as follows:
RECIRC AIR
This mode limits the amount of fresh air that enters
the vehicle be recirculating most of the c1.ir inside
the vehicle. This setting helps cool the air quickly and
helps to limit odors from entering the vehicle. The
air id delivered through the 1/P outlets.
OUTSIDE AIR
This mode draws fresh air in from the outside and
delivers the air through the 1/P outlets. This setting is
used while defrosting or defogging the windows in
order to help clear moisture.
Bl/LEVEL
This mode draws air from the outside. This mode
directs air into the vehicle in 1Wo ways:
• Cooler air is directed toward the upper body
through the 1/P outlets.
82066
• Warmer air is directed through the lower outlets.
HVAC System - Manual 1·121
UPPER
82067
This mode directs most of the air through the
1/P outlets and a small amount of the air to the lower
outlets.
LOWER
82065
This mode directs air into the vehicle in two ways:
• Most of the air is directed through the lower ducts
to the floor area of the vehicle.
• Some of the air is directed toward the windshield
and the side window vents.