2002 DODGE RAM ac compressor

REMOVAL
NOTE: The belt routing schematics are published
from the latest information available at the time of
publication. If anything differs between these sche-
matics and the Belt Routing Label, use the sche-
matics on Belt Routing Label. This label is located
in the engine compartment.
CAUTION: Do not attempt to check belt tension with
a belt tension gauge on vehicles equipped with an
automatic belt tensioner. Refer to Automatic Belt
Tensioner in this group.
Drive belts on these engines are equipped with a
spring loaded automatic belt tensioner (Fig. 12). This
belt tensioner will be used on all belt configurations,
such as with or without power steering or air condi-
tioning. For more information, (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/BELT TENSIONERS -
DESCRIPTION).(1) Attach a socket/wrench to pulley mounting bolt
of automatic tensioner (Fig. 12).
(2) Rotate tensioner assembly clockwise (as viewed
from front) until tension has been relieved from belt.
(3) Remove belt from idler pulley first.
(4) Remove belt from vehicle.
INSTALLATION
CAUTION: When installing the accessory drive belt,
the belt must be routed correctly. If not, engine may
overheat due to water pump rotating in wrong
direction. Refer to (Fig. 13) (Fig. 14) for correct
engine belt routing. The correct belt with correct
length must be used.
(1) Position drive belt over all pulleysexceptidler
pulley. This pulley is located between generator and
A/C compressor.
(2) Attach a socket/wrench to pulley mounting bolt
of automatic tensioner (Fig. 12).
(3) Rotate socket/wrench clockwise. Place belt over
idler pulley. Let tensioner rotate back into place.
Remove wrench. Be sure belt is properly seated on
all pulleys.
(4) Check belt indexing marks.
Fig. 12 Belt Tensioner - 5.9L Gas Engines
1 - IDLER PULLEY
2 - TENSIONER
3 - FAN BLADE
Fig. 13 Belt Routing - 5.9L Engines with A/C
1 - GENERATOR PULLEY
2 - A/C PULLEY
3 - POWER STEERING PULLEY
4 - CRANKSHAFT PULLEY
5 - WATER PUMP PULLEY
6 - TENSIONER PULLEY
7 - IDLER PULLEY
7 - 26 ACCESSORY DRIVEBR/BE
DRIVE BELTS - 5.9L (Continued)

(1) Position drive belt over all pulleysexceptten-
sioner pulley.
(2) Attach a socket/wrench to pulley mounting bolt
of automatic tensioner (Fig. 16).
(3) Rotate socket/wrench counterclockwise. Install
belt over tensioner pulley. Let tensioner rotate back
into place. Remove wrench. Be sure belt is properly
seated on all pulleys.
DRIVE BELTS - 5.9L DIESEL
DIAGNOSIS AND TESTINGÐACCESSORY
DRIVE BELT
VISUAL DIAGNOSIS
When diagnosing serpentine accessory drive belts,
small cracks that run across the ribbed surface of the
belt from rib to rib (Fig. 19), are considered normal.
These are not a reason to replace the belt. However,
cracks running along a rib (not across) arenotnor-
mal. Any belt with cracks running along a rib must
be replaced (Fig. 19). Also replace the belt if it has
excessive wear, frayed cords or severe glazing.
Refer to ACCESSORY DRIVE BELT DIAGNOSIS
CHART for further belt diagnosis.
Fig. 17 Belt RoutingÐWith A/C
1 - AUTOMATIC TENSIONER
2 - GENERATOR PULLEY
3 - IDLER PULLEY
4 - A/C COMPRESSOR PUMP PULLEY
5 - POWER STEERING PUMP PULLEY
6 - WATER PUMP AND FAN PULLEY
7 - CRANKSHAFT PULLEY
8 - AIR PUMP (A.I.R.) PULLEY
Fig. 18 Belt RoutingÐWithout A/C
1 - AUTOMATIC TENSIONER
2 - GENERATOR PULLEY
3 - IDLER PULLEY
4 - POWER STEERING PUMP PULLEY
5 - WATER PUMP AND FAN PULLEY
6 - CRANKSHAFT PULLEY
7 - AIR PUMP (A.I.R.) PULLEY
Fig. 19 Belt Wear Patterns
1 - NORMAL CRACKS BELT OK
2 - NOT NORMAL CRACKS REPLACE BELT
7 - 30 ACCESSORY DRIVEBR/BE
DRIVE BELTS - 8.0L (Continued)

(3) Rotate ratchet and belt tensioner counterclock-
wise. Place belt over water pump pulley. Let ten-
sioner rotate back into place. Remove ratchet. Be
sure belt is properly seated on all pulleys.
VACUUM PUMP - 5.9L DIESEL
DESCRIPTION
The vacuum pump and the power steering pump
are combined into a single assembly on diesel engine
models (Fig. 23). Both pumps are operated by a drive
gear attached to the vacuum pump shaft. The shaft
gear is driven by the camshaft gear.
The vacuum pump is a constant displacement,
vane-type pump. Vacuum is generated by four vanes
mounted in the pump rotor. The rotor is located in
the pump housing and is pressed onto the pump
shaft.
The vacuum and steering pumps are operated by a
single drive gear pressed onto the vacuum pump
shaft. The drive gear is operated by the engine cam-
shaft gear.
The vacuum and power steering pump shafts are
connected by a coupling. Each pump shaft has an
adapter with drive lugs that engage in the coupling.
The vacuum pump rotating components are lubri-
cated by engine oil. Lubricating oil is supplied to the
pump through an oil line at the underside of the
pump housing.
Fig. 20 Belt TensionerÐ5.9L DieselÐTypical
(non-A/C shown)
1 - WATER PUMP
2 - ACCESSORY DRIVE BELT
3 - AUTOMATIC BELT TENSIONER
4 - 3/89SQUARE BOLT
5 - MOUNT. BOLT
Fig. 21 Belt RoutingÐ5.9L Diesel EngineÐWith A/C
1 - GENERATOR PULLEY
2 - WATER PUMP PULLEY
3 - FAN PULLEY
4 - CRANKSHAFT PULLEY
5 - AUTOMATIC TENSIONER
6 - A/C COMPRESSOR PUMP PULLEY
Fig. 22 Belt RoutingÐ5.9L Diesel EngineÐWithout
A/C
1 - GENERATOR PULLEY
2 - FAN PULLEY
3 - CRANKSHAFT PULLEY
4 - AUTOMATIC TENSIONER
5 - WATER PUMP PULLEY
BR/BEACCESSORY DRIVE 7 - 33
DRIVE BELTS - 5.9L DIESEL (Continued)

ENGINE COOLANT TEMP
SENSOR - 5.9L
DESCRIPTION
The Engine Coolant Temperature (ECT) sensor is
used to sense engine coolant temperature. The sensor
protrudes into an engine water jacket.
The ECT sensor is a two-wire Negative Thermal
Coefficient (NTC) sensor. Meaning, as engine coolant
temperature increases, resistance (voltage) in the
sensor decreases. As temperature decreases, resis-
tance (voltage) in the sensor increases.
OPERATION
At key-on, the Powertrain Control Module (PCM)
sends out a regulated 5 volt signal to the ECT sensor.
The PCM then monitors the signal as it passes
through the ECT sensor to the sensor ground (sensor
return).
When the engine is cold, the PCM will operate in
Open Loop cycle. It will demand slightly richer air-
fuel mixtures and higher idle speeds. This is done
until normal operating temperatures are reached.
The PCM uses inputs from the ECT sensor for the
following calculations:
²for engine coolant temperature gauge operation
through CCD or PCI (J1850) communications
²Injector pulse-width
²Spark-advance curves
²ASD relay shut-down times
²Idle Air Control (IAC) motor key-on steps
²Pulse-width prime-shot during cranking
²O2 sensor closed loop times
²Purge solenoid on/off times
²EGR solenoid on/off times (if equipped)
²Leak Detection Pump operation (if equipped)
²Radiator fan relay on/off times (if equipped)²Target idle speed
REMOVAL
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
REFER TO GROUP 7, COOLING.
(1) Partially drain cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(2) Remove air cleaner assembly.
(3) Disconnect electrical connector from sensor
(Fig. 14).
(4)Engines with air conditioning:When
removing the connector from sensor, do not pull
directly on wiring harness. Fabricate an L-shaped
hook tool from a coat hanger (approximately eight
inches long). Place the hook part of tool under the
connector for removal. The connector is snapped onto
the sensor. It is not equipped with a lock type tab.
(5) Remove sensor from intake manifold.
INSTALLATION
(1) Install sensor.
(2) Tighten to 6±8 N´m (55±75 in. lbs.) torque.
(3) Connect electrical connector to sensor. The sen-
sor connector is symmetrical (not indexed). It can be
installed to the sensor in either direction.
(4) Install air cleaner assembly.
(5) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
Fig. 13 Block HeaterÐDiesel Engine
1 - BLOCK HEATER
Fig. 14 Engine Coolant Temperature
1 - GENERATOR
2 - A/C COMPRESSOR
3 - ENGINE COOLANT TEMPERATURE SENSOR
4 - ELEC. CONN.
BR/BEENGINE 7 - 47
ENGINE BLOCK HEATER - 5.9L DIESEL (Continued)

CAUTION: When installing the serpentine accessory
drive belt, the belt must be routed correctly. If not,
engine may overheat due to water pump rotating in
wrong direction. Refer to (Fig. 21) for correct 3.9L,
5.2L and 5.9L engine belt routing. The correct belt
with correct length must be used.
(7) Air Conditioned vehicles; Install generator.
Tighten bolts to 41 N´m (30 ft. lbs.).
(8) Install support bracket (generator mounting
bracket-to-intake manifold) (Fig. 16). Tighten bolts to
54 N´m (40 ft. lbs.) torque.
(9) Install accessory drive belt (Fig. 17)(Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(10) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(11) Connect battery negative cable.
(12) Start and warm the engine. Check for leaks.
Fig. 19 ThermostatÐ5.9L Engines
1 - THERMOSTAT HOUSING
2 - GASKET
3 - INTAKE MANIFOLD
4 - THERMOSTAT
5 - MACHINED GROOVE
Fig. 20 Thermostat PositionÐ5.9L Engines
Fig. 21 Belt RoutingÐ5.9L Engines
1 - IDLER PULLEY
2 - GENERATOR PULLEY
3 - A/C COMPRESSOR PULLEY
4 - IF W/OUT A/C
5 - POWER STEERING PUMP PULLEY
6 - WATER PUMP PULLEY
7 - CRANKSHAFT PULLEY
8 - AUTOMATIC TENSIONER
7 - 50 ENGINEBR/BE
ENGINE COOLANT THERMOSTAT - 5.9L (Continued)

(4) Install the bolt retaining the wiring harness
near top of water pump.
(5) Fill cooling system. Refer to Refilling Cooling
System in this section.
(6) Connect both battery cables.
(7) Start and warm the engine. Check for leaks.
WATER PUMP INLET TUBE -
5.9L
REMOVAL
REMOVAL - WATER PUMP BYPASS HOSE
WITH AIR CONDITIONING
If equipped with A/C, the generator and A/C com-
pressor along with their common mounting bracket
(Fig. 63) must be partially removed. Removing the
generator or A/C compressor from their mounting
bracket is not necessary. Also, discharging the A/C
system is not necessary.Do notremove any refriger-
ant lines from A/C compressor.
WARNING: THE A/C SYSTEM IS UNDER PRESSURE
EVEN WITH THE ENGINE OFF. REFER TO REFRIG-
ERANT WARNINGS IN 24 - HEATING AND AIR CON-
DITIONING.
Fig. 61 Water Pump Removal/Installation
1 - O-RING SEAL (SQUARE)
2 - WATER PUMP
3 - BOLT (2)
Fig. 62 Pump O-ring Seal
1 - O-RING SEAL
2 - GROOVE
3 - WATER PUMP
Fig. 63 Generator - A/C Compressor Mounting
Bracket - Typical
BR/BEENGINE 7 - 73
WATER PUMP - 5.9L DIESEL (Continued)

(1) Disconnect negative battery cable from battery.
(2) Partially drain cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).Do not
waste reusable coolant. If the solution is clean, drain
the coolant into a clean container for reuse.
(3) Remove upper radiator hose clamp at radiator.
A special clamp tool must be used to remove the con-
stant tension clamps. Remove hose at radiator.
(4) Disconnect throttle cable from clip at radiator
fan shroud.
(5) Unplug wiring harness from A/C compressor.
(6) Remove the air cleaner assembly.
(7) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(8)5.9L V-8 LDC-Gas:The drive belt idler pulley
must be removed to gain access to one of the A/C
compressor/generator bracket mounting bolts.
Remove the idler pulley bolt and remove idler pulley
(Fig. 64).(9)5.9L HDC-Gas:The automatic belt tensioner/
pulley assembly must be removed to gain access to
one of the A/C compressor/generator bracket mount-
ing bolts. Remove the tensioner mounting bolt (Fig.
65) and remove tensioner.
(10) Remove the engine oil dipstick tube mounting
bolt at the side of the A/C-generator mounting
bracket.
(11) Disconnect throttle body control cables.
(12) Remove heater hose coolant return tube
mounting bolt (Fig. 66) (Fig. 67) and remove tube
from engine. Discard the old tube O-ring.
(13) Remove bracket-to-intake manifold bolts
(number 1 and 2 (Fig. 63).
(14) Remove remaining bracket-to-engine bolts
(Fig. 68) (Fig. 69).
Fig. 64 Idler Pulley - 5.9L V-8 LDC-Gas Engine
Fig. 65 Belt Tensioner - 5.9L HDC-Gas Engine
1 - PULLEY BOLT
2 - IDLER PULLEY
3 - TENSIONER PULLEY
4 - TENSIONER
5 - TENSIONER MOUNTING BOLT
7 - 74 ENGINEBR/BE
WATER PUMP INLET TUBE - 5.9L (Continued)

(10)5.9L HDC-Gas:Install automatic belt ten-
sioner assembly to mounting bracket. A dowel pin is
located on back of tensioner (Fig. 71). Align this to
dowel hole (Fig. 72) in tensioner mounting bracket.
Tighten bolt to 41 N´m (30 ft. lbs.) torque.(11) Install drive belt (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION).
CAUTION: When installing the serpentine accessory
drive belt, the belt must be routed correctly. If not,
the engine may overheat due to the water pump
rotating in the wrong direction (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION). The correct belt with the correct length must
be used.
(12) Install air cleaner assembly.
(13) Install upper radiator hose to radiator.
(14) Connect throttle cable to clip at radiator fan
shroud.
(15) Connect wiring harness to A/C compressor.
(16) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(17) Start and warm the engine. Check for leaks.
INSTALLATION - WATER PUMP BYPASS HOSE
WITHOUT AIR CONDITIONING
(1) Position bypass hose clamps to the center of
hose.
(2) Install bypass hose to engine.
(3) Secure both hose clamps.
(4) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(5) Start and warm the engine. Check for leaks.
Fig. 71 Tensioner Dowel Pin - 5.9L HDC-Gas Engine
1 - BELT TENSIONER
2 - DOWEL PIN
Fig. 72 Tensioner Mounting
1 - DOWEL PIN HOLE
2 - TENSIONER MOUNTING BRACKET
BR/BEENGINE 7 - 77
WATER PUMP INLET TUBE - 5.9L (Continued)