Peterbilt Medium Duty Trucks Operator's Manual after 1-07

Operating Instructions
Defogging
CAUTION: During extreme cold weather, do not
blow hot air onto cold windshields. This could
crack the glass. Turn the air direction lever to
Defrost and adjust the fan speed accordingly
while the engine warms. If the engine is already
warm, move the temperature selector to Cool,
then gradually increase the temperature when
you see that the windshield is starting to warm
up.
NOTE: The air conditioning system is active when
the Defrost mode is selected.
To defog the windshield: select air direction mode 4 or 5 and
turn the fan speed switch (A) to high. Set the temperature
knob (C) to hot (red position on the control). The air conditioner
(if equipped) is automatically activated to remove moisture
from the cab. After the windshield is clear, adjust the
controls as desired.
Cooling
Heating and Air Conditioning
To cool the cab: turn on the air conditioner (if equipped)
(switch E), set the temperature knob (C) to cool (blue side),
and the fan (A) to high until the cab becomes cool—adjust as
desired.
For Efficient Cooling:
HEATING A/C CONTROL
CONTROLS
HEATING COOLING DEFOGGING
MAX NML MAX NML MAX NML
Fan Speed (A) High (4) Adjust High (4) Adjust High (4) Adjust
Air Direction
Mode (B)
Panel
(1)
Panel
or Bi-
Level
(2)
Adjust
Adjust
Defrost
(5)
Defrost
or Bi-
Level (4)
Temperature (C) Warm Adjust Cool Adjust Warm Adjust
Air Circulation
Mode (D)
Recirc Fresh Record Fresh Recirc Fresh
Air Conditioner -
AC (E)
OFF OFF ON ON — —
1. Ensure all heater/air conditioner controls are off.
2. Start the engine. Allow time for warm–up.
Medium Duty (R10/06) Y53-6008 – 41 –