Peterbilt 579 - Page 160

HEATING AND AIR CONDITIONING
3
For Maximum Heating
Step 1:
Adjust the fan speed to high by
rotating the fan control dial clockwise.
Step 2: Set the air distribution
dial to the oor setting.
Step 3: Adjust the air temperature
to maximum heat by rotating the
temperature dial clockwise.
NOTE
The engine must be at operating tem-
perature for maximum heating. If op-
erating in AUTO mode, heating airow
is not allowed until the engine warms
sufciently to provide required coolant
temperatures.
Air Dehumidication
The HVAC
system can be used to
reduce the humidity level of the cab
and clear fog from the windshield.
Step 1:
Adjust fan speed to
the desired airow setting.
Step 2: Engage the A/C compressor
by pressing the air conditioner button.
Step 3: Set the air source to outside
air mode by pressing the outside
air / recirculation air button. The
button indicator light should NOT be
illuminated.
NOTE
That the A/C compressor may not en-
gage when the outside temperature is
below 34ºF (1ºC).
Cab Air Distribution
Equal distribution
of air is important
in maintaining a constant cab interior
temperature. For best performance, all
vents should remain open to allow the
AUTO mode to function properly.
To
maintain the selected cab
temperature the AUTO mode may
provide an air temperature from the
vents that differs from the temperature
set point. To ensure proper operation,
it is recommended that the driver
redirects the air instead of adjusting
the temperature set point or closing
the vent. The system may have
difculties in obtaining the desired
cabin temperature if the temperature
setting is repeatedly changed.
3-88 Y53-6047–2C (04/13)