Peterbilt Model 320 Operator's Manual after 8-07 - Peterbilt Motors ...

Air Suspension Deflate Switch (Dump Valve)
PART 4: CONTROLS AND DISPLAYS
Engine Fan Switch
WARNING! Do not work on the fan with the engine
running. Anyone near the engine fan when
it turns on could be badly injured. If it is set
at ON, it will turn on any time the ignition key
switch is turned to the ON position. In AUTO-
MATIC, it could engage suddenly without warning.
Before turning on the ignition or switching
from AUTOMATIC to ON, be sure no one is near
the fan.
03023
The engine fan switch allows you to control the engine fan
manually or automatically. With the ignition key switch ON
and the fan switch in the ON position, the engine fan will
be on regardless of engine temperature. With the engine
fanswitchintheAUTOMATICposition,theenginefanwill
automatically turn on when the engine coolant reaches a
temperature of about 200° F (93° C).
CAUTION: The fan or equipment near it could be
damaged if the fan turns on suddenly when you
don’t expect it. Keep all tools and equipment
away from the fan.
NOTE: Do not operate the engine fan in the manual
(ON) position for extended periods of time. The fan
hub was designed for intermittent operation. Sustained
operation will shorten the fan hub’s service
life as well as reduce fuel economy.
– 30 – Y53-6015 R(08/07)