Global Machinery Company Sierra 1999 - Manual (Page 165)

yellow blue
3-5
The system will automatically switch to the recirculation
mode to lower the system load and improve interior
comfort. The OUTSIDE AIR and RECIRCULATION
button LEDs will not change. The system will return to
the OUTSIDE AIR function when the system load
is reduced.
A/C: Press this button to turn the air conditioning
on and off. The system will cool and dehumidify the air
inside the vehicle when the A/C light is on.
Air conditioning will be automatically disabled when
the outside temperature drops below a level at which air
conditioning is ineffective.
Air Conditioning
On hot days, open the windows long enough to let hot
air inside 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.
The RECIRCULATION button, below the fan knob,
allows the air inside your vehicle to be recirculated. This
setting helps to maximize your air conditioner’s
performance and your vehicle’s fuel economy. This
setting also cools air the fastest and can be used to keep
unwanted odors and/or dust from entering the vehicle.
When using the air conditioner, turn off the
RECIRCULATION button after the vehicle reaches a
comfortable interior temperature. When the right knob
on the control panel is between HEATER and
DEFROST, the recirculation feature will not function to
reduce window fogging.
The A/C button, below the mode knob, allows the air
coming into your vehicle to be cooled. This setting is
useful for normal cooling on hot days. When you use
A/C with the RECIRCULATION button pushed in, turn
off recirculation as soon as the vehicle reaches a
comfortable interior temperature.
Maximum air conditioning performance is obtained by
pressing the A/C button, the RECIRCULATION button
and turning the temperature knob fully counterclockwise
to the blue area. This setting also cools air the fastest.
After the vehicle’s interior reaches a comfortable
temperature, press the OUTSIDE AIR button to place
the air conditioning system in the normal mode.
Passenger Compartment Air Filter (If Equipped)
Your vehicle may be equipped with a passenger
compartment air filter, which filters outside air entering
the vehicle. For information on replacing the filter see
“Passenger Compartment Air Filter” in the Index.