Chrysler DODGE D150 1993 Service Manual page 272

C O O L I N G S Y S T E M
C O N T E N T S
page
DIAGNOSIS . . . 4
ENGINE ACCESSORY DRIVE BELTS
40
ENGINE BLOCK HEATERS 48
GENERAL INFORMATION
Throughout this group, references are made to partic­
ular vehicle models by alphabetical designation or by
the particular vehicle nameplate. A chart showing a
breakdown of alphabetical designations is included in
the Introduction section at the beginning of this man­
ual.
5.9L gas powered engines will be' referred to as ei­
ther: LDC (Light Duty Cycle) or HDC (Heavy Duty
Cycle).
COOLING SYSTEM
The cooling system regulates engine operating tem­
perature. It allows the engine to reach normal oper-
page
SERVICE PROCEDURES 15
SPECIFICATIONS ; 49
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre­
vents overheating.
The cooling system also provides a means of heat­
ing the passenger compartment and cooling the auto­
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
An optional factory installed maximum duty cool­
ing package is available on most models. This pack­
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures.
N O T E : HEATER
C O O L A N T F L O W
CIRCUIT IS A L W A Y S
O P E N EXCEPT
W H E N I N M A X . A / C
O R O F F M O D E S
HEATER
INTAKE MANIFOLD
C O O L A N T FLOW "METERED"
FROM REAR TO
FRONT A N D BELOW
EXHAUST HEAT
CROSSOVER
S H U T O F F V A L V E
A / C O N L Y
C O O L A N T FLOW - PUMP TO
CYLINDER BLOCK, UP THROUGH
CYLINDER H E A D S TO INTAKE
MANIFOLD WATER BOX TO
R A D I A T O R - T O PUMP
• B Y P A S S
THERMOSTAT C L O S E D - H I G H FLOW
THERMOSTAT O P E N - L O W FLOW
J9207-18
Fig. 1 Cooling System Routing—3.9U5.2L Engine—Typical