Peterbilt 579 - Page 159

HEATING AND AIR CONDITIONING
Manual Windshield
Defrosting/Defogging
The manual
defrost/defogging mode
differs from the MAX defrost mode
by allowing the driver to select an air
temperature other than full heat. This
allows the driver to maintain a constant
cab temperature while defrosting
the windshield. Note however that
performance may be reduced.
Step 1:
Adjust the fan speed to high by
rotating the fan control dial clockwise.
Step 2: Set the air distribution
dial to the defrost mode setting.
This automatically engages the
outside air and A/C compressor.
Step 3: Adjust the temperature dial to
add heat as needed. For maximum
performance, adjust the temperature
to maximum heat by rotating the
temperature dial clockwise.
The driver
may also use the
oor/defrost setting on the air control
dial to
maintain a clear windshield while
providing heat to the oor. This setting
may be helpful in conditions where the
windshield re-fogs. To increase the
effectiveness of the defroster, engage
the A/C compressor.
For Maximum
Cooling
Step 1:
Adjust the fan speed to high by
rotating the fan control dial clockwise.
Step 2: Set the air distribution
dial to the panel setting.
Step 3: Adjust the air temperature
to maximum cool by rotating the
temperature dial counterclockwise.
Step 4: Engage the A/C compressor
by pressing the air conditioner button.
Step 5: Set the air source to
recirculation mode by pressing the
outside air / recirculation air button.
The button indicator light should be
illuminated.
3
(04/13) Y53-6047–2C 3-87