2002 DODGE RAM heater

CONDITION POSSIBLE CAUSES CORRECTION
13. Brakes dragging. 13. Check brakes. (Refer to 5 -
BRAKES/HYDRAULIC/
MECHANICAL - DIAGNOSIS AND
TESTING)
TEMPERATURE GAUGE READING
INCONSISTENT ( ERRATIC,
CYCLES OR FLUCTUATES)1. Heavy duty cooling system,
extream cold ambient (outside)
temperature or heater blower motor
in high position.1. None. System operating normaly.
2. Temperature gauge or gauge
sensor defective.2. Check gauge. (Refer to 8 -
ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND
TESTING)
3. Temporary heavy usage or load. 3. None. Normal condition.
4. Air traped in cooling system. 4. Fill cooling system (Refer to 7 -
COOLING - STANDARD
PROCEDURE).
5. Water pump 5. Replace water pump.
6. Air leak on suction side of water
pump.6. Check for leak. (Refer to 7 -
COOLING - DIAGNOSIS AND
TESTING)
RADIATOR CAP LEAKING STEAM
AND /OR COOLANT INTO
RESERVOIR BOTTLE.
(TEMPERATURE GAUGE MAY
READ HIGH)1. Radiator cap defective. 1. Replace radiator cap.
2. Radiator neck surface damaged. 2. Replace radiator.
HOSE OR HOSES COLLAPSE
WHEN ENGINE IS COOLING.1. Vacuum created in cooling
system on engine cool-down is not
being relieved through coolant
reservior/overflow system.1. Replace radiator cap, check vent
hose between radiator and reservoir
bottle for blockage also check
reservoir bottle vent for blockage.
NOISY FAN 1. Fan blade(s) loose, damaged. 1. Replace fan blade assembly.
2. Thermal viscous fan drive. 2. None. Normal condition.
3. Fan blades striking surrounding
objects.3. Locate contact point and repair
as necessary.
4. Thermal viscous fan drive
bearing.4. Replace viscous fan drive
assembly.
5. Obstructed air flow through
radiator.5. Remove obstruction.
INADEQUATE AIR CONDITIONER
PERFORMANCE (COOLING
SYSTEM SUSPECTED)1. Radiator and/or A/C condenser
air flow obstructed.1. Remove obstruction and/or clean.
7 - 14 COOLINGBR/BE
COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
2. Thermal viscous fan drive not
working.2. Check fan drive. (Refer to 7 -
COOLING/ENGINE/FAN DRIVE
VISCOUS CLUTCH - DIAGNOSIS
AND TESTING)
3. Air seals around radiator
damaged or missing.3. Inspect air seals, repair or
replace as necessary.
INADEQUATE HEATER
PERFORMANCE. GUAGE MAY OR
MAY NOT READ LOW.1. Heavy duty cooling system, and
cooler ambient temperatures.1. None. Normal condition.
2. Obstruction in heater hoses. 2. Remove hoses, remove
obstruction.
3. Water pump damaged. 3. Replace water pump.
HEAT ODOR 1. Damaged or missing drive line
heat shields.1. Repair or replace damaged or
missing heat shields.
2. Thermal viscous fan drive
damaged.2. Check thermal viscous fan drive.
(Refer to 7 - COOLING/ENGINE/
FAN DRIVE VISCOUS CLUTCH -
DIAGNOSIS AND TESTING)
STANDARD PROCEDURE
STANDARD PROCEDURE - DRAINING COOLING
SYSTEM 5.9L/8.0L ENGINES
WARNING: DO NOT REMOVE CYLINDER BLOCK
DRAIN PLUGS OR LOOSEN RADIATOR DRAIN-
COCK WITH SYSTEM HOT AND UNDER PRESSURE.
SERIOUS BURNS FROM COOLANT CAN OCCUR.
DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean container for reuse.
(1) Remove radiator pressure cap.
(2) Loosen radiator petcock.
(3) Remove cylinder block drain plugs. Refer to
(Fig. 7).
STANDARD PROCEDUREÐDRAINING COOLING
SYSTEM 5.9L DIESEL ENGINE
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAIN PLUG WITH SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM COOLANT
CAN OCCUR.
DO NOT WASTE reusable coolant. If the solution
is clean, drain the coolant into a clean container for
reuse.
(1) Start the engine and place the heater control
temperature selector in the Full-On position. Vacuum
is needed to actuate the heater controls.(2) Turn the ignition off.
(3) Do not remove radiator cap when draining cool-
ant from reserve/overflow tank. Open radiator drain
plug and when tank is empty, remove radiator cap. If
the coolant reserve/overflow tank does not drain,
(Refer to 7 - COOLING - DIAGNOSIS AND TEST-
ING). The coolant need not be removed from tank
unless the system is being refilled with fresh mix-
ture.
(4) Remove radiator pressure cap.
Fig. 7 Cylinder Block Drain Plug - 5.9L Engines
1 - BLOCK DRAIN PLUG
BR/BECOOLING 7 - 15
COOLING (Continued)

The coolant reserve/overflow system provides a
quick method for determining coolant level without
removing radiator pressure cap. With engine not run-
ning, open the coolant recovery bottle cap and
remove coolant level indicator dipstick to observe
coolant level in coolant recovery bottle. The coolant
level should be between ADD and FULL marks. If
the coolant level is at or below the ADD mark, fill
the recovery bottle with a 50/50 mixture of antifreeze
and water ONE QUART AT A TIME. Repeat this pro-
cedure until the coolant level is at the FULL mark
(Fig. 8).
STANDARD PROCEDURE - COOLING SYSTEM
CLEANING/REVERSE FLUSHING
CLEANING
Drain cooling system and refill with water. Run
engine with radiator cap installed until upper radia-
tor hose is hot. Stop engine and drain water from
system. If water is dirty, fill system with water, run
engine and drain system. Repeat until water drains
clean.
REVERSE FLUSHING
Reverse flushing of cooling system is the forcing of
water through the cooling system. This is done using
air pressure in the opposite direction of normal cool-
ant flow. It is usually only necessary with very dirty
systems with evidence of partial plugging.
REVERSE FLUSHING RADIATOR
Disconnect radiator hoses from radiator inlet and
outlet. Attach a section of radiator hose to radiator
bottom outlet fitting and insert flushing gun. Con-
nect a water supply hose and air supply hose to
flushing gun.
CAUTION: Internal radiator pressure must not
exceed 138 kPa (20 psi) as damage to radiator may
result.
Allow radiator to fill with water. When radiator is
filled, apply air in short blasts. Allow radiator to
refill between blasts. Continue this reverse flushing
until clean water flows out through rear of radiator
cooling tube passages. Have radiator cleaned more
extensively by a radiator repair shop.
REVERSE FLUSHING ENGINE
Drain cooling system. Remove thermostat housing
and thermostat. Install thermostat housing. Discon-
nect radiator upper hose from radiator and attach
flushing gun to hose. Disconnect radiator lower hose
from water pump and attach a lead-away hose to
water pump inlet fitting.
CAUTION: On vehicles equipped with a heater water
control valve, be sure heater control valve is closed
(heat off). This will prevent coolant flow with scale
and other deposits from entering heater core.
Connect water supply hose and air supply hose to
flushing gun. Allow engine to fill with water. When
engine is filled, apply air in short blasts, allowing
system to fill between air blasts. Continue until clean
water flows through the lead away hose.
Remove lead away hose, flushing gun, water sup-
ply hose and air supply hose. Remove thermostat
housing and install thermostat. Install thermostat
housing with a replacement gasket. Refer to Thermo-
stat Replacement. Connect radiator hoses. Refill cool-
ing system with correct antifreeze/water mixture.
Refer to Refilling the Cooling System.
CHEMICAL CLEANING
In some instances, use a radiator cleaner (Mopar
Radiator Kleen or equivalent) before flushing. This
will soften scale and other deposits and aid flushing
operation.
CAUTION: Follow manufacturers instructions when
using these products.
STANDARD PROCEDURE - COOLANT
SELECTION - ADDITIVES
The use of aluminum cylinder blocks, cylinder
heads and water pumps requires special corrosion
protection. Only MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula (glycol base coolant with
corrosion inhibitors called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% distilled water to obtain to obtain a
freeze point of -37ÉC (-35ÉF). If it loses color or
becomes contaminated, drain, flush, and replace with
fresh properly mixed coolant solution.
CAUTION: Do not use coolant additives that are
claimed to improve engine cooling.
BR/BECOOLING 7 - 17
COOLING (Continued)

SPECIFICATIONS
TORQUE
DESCRIPTION N´m Ft. In.
Lbs. Lbs
Belt Tensioner Pulley 5.9L
Engine-Bolt 61 45 Ð
Belt Tensioner Pulley 8.0L
EngineÐ
Bolt 88 65 Ð
Belt Tensioner to Mounting
BracketÐ
Bolt 5.9L Engine 67 50 Ð
Belt Tensioner to Mounting
BracketÐ
Bolt 8.0L Engine 41 30 Ð
Block HeaterÐScrew Gas
Engines2Ð17
Block HeaterÐHex Diesel
Engine43 32 Ð
Fan Shroud to Radiator
MountingÐ
Bolts 6 Ð 50
Heater Hose Fitting at Water
PumpÐ(8.0L) 16 Ð 142
Idler Pulley MountingÐBolts
Gas Engines 61 45 Ð
Radiator MountingÐBolts 11 Ð 95
Thermal Viscous Fan to
HubÐ(Diesel)57 42 Ð
Thermostat HousingÐBolts
5.9L 23 Ð 200
Thermostat HousingÐBolts
8.0L25 Ð 220
Thermostat HousingÐBolts
Diesel24 Ð 212
Water Pump MountingÐBolts
Gas Engines 40 30 Ð
Water Pump MountingÐBolts
Diesel24 Ð 212
SPECIAL TOOLS
COOLING
SPANNER WRENCH 6958
Adapter Pins 8346
Pliers 6094
Pressure Tester 7700±A
7 - 18 COOLINGBR/BE
COOLING (Continued)

ENGINE
TABLE OF CONTENTS
page page
COOLANT
DESCRIPTION - ENGINE COOLANT.........39
OPERATION...........................40
COOLANT RECOVERY CONTAINER - 3.9L/5.2L/
5.9L/5.9L DIESEL
DESCRIPTION.........................40
OPERATION...........................40
REMOVAL.............................40
INSTALLATION.........................41
COOLANT RECOVERY CONTAINER - 8.0L
DESCRIPTION.........................41
OPERATION...........................41
RADIATOR FAN - 5.9L/8.0L
REMOVAL.............................41
CLEANING............................42
INSPECTION..........................42
INSTALLATION.........................42
RADIATOR FAN - 5.9L DIESEL
REMOVAL.............................43
CLEANING............................43
INSPECTION..........................43
INSTALLATION.........................44
ENGINE BLOCK HEATER - 5.9L
DESCRIPTION.........................44
OPERATION...........................44
REMOVAL.............................44
INSTALLATION.........................44
ENGINE BLOCK HEATER - 8.0L
DESCRIPTION.........................45
OPERATION...........................45
REMOVAL.............................45
INSTALLATION.........................45
ENGINE BLOCK HEATER - 5.9L DIESEL
DESCRIPTION.........................46
OPERATION...........................46
REMOVAL.............................46
INSTALLATION.........................46
ENGINE COOLANT TEMP SENSOR - 5.9L
DESCRIPTION.........................47
OPERATION...........................47
REMOVAL.............................47
INSTALLATION.........................47
ENGINE COOLANT THERMOSTAT - 5.9L
DESCRIPTION.........................48
OPERATION...........................48
DIAGNOSIS AND TESTINGÐTHERMOSTAT . . . 48
REMOVAL.............................48
INSTALLATION.........................49ENGINE COOLANT THERMOSTAT - 8.0L
DESCRIPTION.........................51
OPERATION...........................51
DIAGNOSIS AND TESTINGÐTHERMOSTAT . . . 51
REMOVAL.............................51
INSTALLATION.........................52
ENGINE COOLANT THERMOSTAT - 5.9L
DIESEL
DESCRIPTION.........................53
OPERATION...........................53
DIAGNOSIS AND TESTINGÐTHERMOSTAT . . . 53
REMOVAL.............................54
INSTALLATION.........................54
FAN DRIVE VISCOUS CLUTCH - 5.9L/8.0L
DESCRIPTION.........................55
OPERATION...........................55
DIAGNOSIS AND TESTING - VISCOUS FAN
DRIVE..............................55
FAN DRIVE VISCOUS CLUTCH - 5.9L DIESEL
DESCRIPTION.........................56
OPERATION...........................56
DIAGNOSIS AND TESTING - VISCOUS FAN
DRIVE..............................57
RADIATOR - 5.9L
DESCRIPTION.........................58
OPERATION...........................58
DIAGNOSIS AND TESTINGÐRADIATOR
COOLANT FLOW......................58
REMOVAL.............................58
CLEANING............................59
INSPECTION..........................60
INSTALLATION.........................60
RADIATOR - 8.0L
DESCRIPTION.........................60
OPERATION...........................60
DIAGNOSIS AND TESTINGÐRADIATOR
COOLANT FLOW......................60
REMOVAL.............................60
CLEANING............................61
INSPECTION..........................61
INSTALLATION.........................61
RADIATOR - 5.9L DIESEL
DESCRIPTION.........................62
OPERATION...........................62
DIAGNOSIS AND TESTINGÐRADIATOR
COOLANT FLOW......................62
REMOVAL.............................62
CLEANING............................64
INSPECTION..........................64
7 - 38 ENGINEBR/BE

INSTALLATION
(1) Install fan blade assembly to viscous fan drive.
Tighten mounting bolts to 23 N´m (17 ft. lbs.) torque.
(2) Position the fan shroud and fan blade/viscous
fan drive to the vehicle as an assembly.
(3) Install viscous fan drive assembly on fan hub
shaft (Fig. 7). Tighten mounting nut to 57 N´m (42 ft.
lbs.) torque.
(4) Install fan shroud bolts into position and
tighten the mounting bolts to 6 N´m (50 in. lbs.)
torque.
(5) Connect the battery negative cables.
NOTE:
Viscous Fan Drive Fluid Pump Out Requirement:
After installing a new viscous fan drive, bring the
engine speed up to approximately 2000 rpm and
hold for approximately two minutes. This will
ensure proper fluid distribution within the drive.
ENGINE BLOCK HEATER - 5.9L
DESCRIPTION
WARNING: DO NOT OPERATE ENGINE UNLESS
BLOCK HEATER CORD HAS BEEN DISCONNECTED
FROM POWER SOURCE AND SECURED IN PLACE.
THE POWER CORD MUST BE SECURED IN ITS
RETAINING CLIPS AND ROUTED AWAY FROM
EXHAUST MANIFOLDS AND MOVING PARTS.
An optional engine block heater is available on all
models. The heater is equipped with a power cord.
The heater is mounted in a core hole of the engine
cylinder block (in place of a freeze plug) with the
heating element immersed in engine coolant. The
cord is attached to an engine compartment compo-
nent with tie-straps.
The 5.9L gas powered engine has the block heater
located on the right side of engine next to the oil fil-
ter (Fig. 8).
OPERATION
The heater warms the engine coolant providing
easier engine starting and faster warm-up in low
temperatures. Connecting the power cord to a
grounded 110-120 volt AC electrical outlet with a
grounded three wire extension cord provides the elec-
tricity needed to heat the element..
REMOVAL
(1) Disconnect battery negative cable.
(2) Drain coolant (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).(3) Remove power cord from heater by unplugging
(Fig. 9).
(4) Loosen (but do not completely remove) the
screw at center of block heater (Fig. 9).
(5) Remove block heater by carefully prying from
side-to-side. Note direction of heating element coil
(up or down). Element coil must be installed correctly
to prevent damage.
INSTALLATION
(1) Clean and inspect the block heater hole.
(2) Install new O-ring seal(s) to heater in gasoline
engines.
(3) Insert block heater into cylinder block.
(4) With heater fully seated, tighten center screw
to 2 N´m (17 in. lbs.).
(5) Fill cooling system with recommended coolant.
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(6) Start and warm the engine.
(7) Check block heater for leaks.
Fig. 8 Engine Block Heater
1 - FREEZE PLUG HOLE
2 - BLOCK HEATER
3 - SCREW
4 - POWER CORD (120V AC)
5 - HEATING COIL
6 - OIL FILTER
7 - 44 ENGINEBR/BE
RADIATOR FAN - 5.9L DIESEL (Continued)

ENGINE BLOCK HEATER - 8.0L
DESCRIPTION
An optional engine block heater is available on all
models. The heater is equipped with a power cord.
The heater is mounted in a core hole of the engine
cylinder block (in place of a freeze plug) with the
heating element immersed in engine coolant. The
cord is attached to an engine compartment compo-
nent with tie-straps.
The 8.0L V-10 engine has the block heater located
on the right side of engine next to the engine oil dip-
stick tube (Fig. 10).
WARNING: DO NOT OPERATE ENGINE UNLESS
BLOCK HEATER CORD HAS BEEN DISCONNECTED
FROM POWER SOURCE AND SECURED IN PLACE.
THE POWER CORD MUST BE SECURED IN ITS
RETAINING CLIPS AND ROUTED AWAY FROM
EXHAUST MANIFOLDS AND MOVING PARTS.
OPERATION
The heater warms the engine coolant providing
easier engine starting and faster warm-up in low
temperatures. Connecting the power cord to agrounded 110-120 volt AC electrical outlet with a
grounded three wire extension cord provides the elec-
tricity needed to heat the element..
REMOVAL
(1) Disconnect battery negative cable.
(2) Drain coolant from radiator and cylinder block
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(3) Remove power cord from heater by unplugging
(Fig. 11).
(4) Loosen (but do not completely remove) the
screw at center of block heater (Fig. 11).
(5) Remove block heater by carefully prying from
side-to-side. Note direction of heating element coil
(up or down). Element coil must be installed correctly
to prevent damage.
INSTALLATION
(1) Clean and inspect the block heater hole.
(2) Install new O-ring seal(s) to heater in gasoline
engines.
(3) Insert block heater into cylinder block.
(4) With heater fully seated, tighten center screw
to 2 N´m (17 in. lbs.).
Fig. 9 Engine Block Heater
1 - FREEZE PLUG HOLE
2 - BLOCK HEATER
3 - SCREW
4 - POWER CORD (120V AC)
5 - HEATING COIL
6 - OIL FILTER
Fig. 10 Engine Block HeaterÐ8.0L V-10 Engine
1 - FREEZE PLUG HOLE
2 - SCREW
3 - POWER CORD (120V AC)
4 - BLOCK HEATER
5 - HEATING COIL
BR/BEENGINE 7 - 45
ENGINE BLOCK HEATER - 5.9L (Continued)

(5) Fill cooling system with recommended coolant
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(6) Start and warm the engine.
(7) Check block heater for leaks.
ENGINE BLOCK HEATER - 5.9L
DIESEL
DESCRIPTION
WARNING: DO NOT OPERATE ENGINE UNLESS
BLOCK HEATER CORD HAS BEEN DISCONNECTED
FROM POWER SOURCE AND SECURED IN PLACE.
THE POWER CORD MUST BE SECURED IN ITS
RETAINING CLIPS AND ROUTED AWAY FROM
EXHAUST MANIFOLDS AND MOVING PARTS.
An optional engine block heater is available on all
models. The heater is equipped with a power cord.
The heater is mounted in a threaded hole of the
engine cylinder block with the heating element
immersed in engine coolant. The cord is attached to
an engine compartment component with tie-straps.The 5.9L diesel engine has the block heater located
on the right side of the engine below the exhaust
manifold next to the oil cooler (Fig. 12).
OPERATION
The heater warms the engine coolant providing
easier engine starting and faster warm-up in low
temperatures. Connecting the power cord to a
grounded 110-120 volt AC electrical outlet with a
grounded three wire extension cord provides the elec-
tricity needed to heat the element..
REMOVAL
(1) Disconnect the battery negative cables.
(2) Drain coolant from radiator and cylinder block
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(3) Unscrew the power cord retaining cap and dis-
connect cord from heater element.
(4) Using a suitable size socket, loosen and remove
the block heater element (Fig. 13).
INSTALLATION
(1) Clean and inspect the threads in the cylinder
block.
(2) Coat heater element threads with Mopart
Thread Sealer with Teflon.
(3) Screw block heater into cylinder block and
tighten to 43 N´m (32 ft. lbs.).
(4) Connect block heater cord and tighten retain-
ing cap.
(5) Fill cooling system with recommended coolant
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(6) Start and warm the engine.
(7) Check block heater for leaks.
Fig. 11 Block HeaterÐ8.0L V-10 Engine
1 - FREEZE PLUG HOLE
2 - SCREW
3 - POWER CORD (120V AC)
4 - BLOCK HEATER
5 - HEATING COIL
Fig. 12 Engine Block HeaterÐ5.9L Diesel Engine
1 - BLOCK HEATER
7 - 46 ENGINEBR/BE
ENGINE BLOCK HEATER - 8.0L (Continued)