1998 DODGE RAM 1500 Cooling wiring

and coil are the only serviced parts on the compres-
sor.
A/C compressor clutch engagement is controlled by
several components: the A/C-heater control, A/C pres-
sure transducer, A/C compressor clutch relay, evapo-
rator temperature sensor and the powertrain control
module (PCM). The PCM may delay compressor
clutch engagement for up to thirty seconds (Refer to
8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/POWERTRAIN CONTROL MODULE -
DESCRIPTION).
DIAGNOSIS AND TESTING - A/C COMPRESSOR
CLUTCH COIL
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information). The battery must
be fully-charged before performing the following
tests. Refer to Battery for more information.
(1) Connect an ammeter (0 to 10 ampere scale) in
series with the clutch coil terminal. Use a voltmeter
(0 to 20 volt scale) with clip-type leads for measuring
the voltage across the battery and the compressor
clutch coil.
(2) With the A/C-heater controls in any A/C mode,
and the blower motor switch in the lowest speed
position, start the engine and run it at normal idle.
(3) The compressor clutch coil voltage should read
within 0.2 volts of the battery voltage. If there is
voltage at the clutch coil, but the reading is not
within 0.2 volts of the battery voltage, test the clutch
coil feed circuit for excessive voltage drop and repair
as required. If there is no voltage reading at the
clutch coil, use a DRB IIItscan tool and (Refer to
Appropriate Diagnostic Information) for testing of thecompressor clutch circuit and PCM control. The fol-
lowing components must be checked and repaired as
required before you can complete testing of the clutch
coil:
²Fuses in the junction block and the power distri-
bution center (PDC)
²A/C-heater control
²A/C compressor clutch relay
²A/C pressure transducer
²Evaporator temperature sensor
²Powertrain control module (PCM)
(4) The compressor clutch coil is acceptable if the
current draw measured at the clutch coil is within
specifications with the electrical system voltage at
11.5 to 12.5 volts (Refer to 24 - HEATING & AIR
CONDITIONING - SPECIFICATIONS). This should
only be checked with the work area temperature at
21É C (70É F). If system voltage is more than 12.5
volts, add electrical loads by turning on electrical
accessories until the system voltage drops below 12.5
volts.
(a) If the clutch coil current reading is above
specifications, the coil is shorted and should be
replaced.
(b) If the clutch coil current reading is zero, the
coil is open and should be replaced.
STANDARD PROCEDURE - A/C COMPRESSOR
CLUTCH BREAK-IN
After a new compressor clutch has been installed,
cycle the compressor clutch approximately twenty
times (five seconds on, then five seconds off). During
this procedure, set the A/C-heater control to the
Recirculation Mode, the blower motor switch in the
highest speed position, and the engine speed at 1500
to 2000 rpm. This procedure (burnishing) will seat
the opposing friction surfaces and provide a higher
compressor clutch torque capability.
REMOVAL
The refrigerant system can remain fully-charged
during compressor clutch, rotor, or coil replacement.
The compressor clutch can be serviced in the vehicle.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(3) Disconnect the compressor clutch coil wire har-
ness connector.
(4) Remove the bolts that secure the compressor to
the mounting bracket.
(5) Remove the compressor from the mounting
bracket. Support the compressor in the engine com-
partment while servicing the clutch.
Fig. 1 Compressor Clutch - Typical
1 - CLUTCH PLATE
2 - SHAFT KEY (not used on KJ)
3 - ROTOR
4 - COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
24 - 10 CONTROLSDR
A/C COMPRESSOR CLUTCH/COIL (Continued)

ING/CONTROLS/BLOWER MOTOR RESISTOR
BLOCK - INSTALLATION).
(5) If removed, install the blower motor (Refer to
24 - HEATING & AIR CONDITIONING/DISTRIBU-
TION/BLOWER MOTOR - INSTALLATION).
(6) Install the HVAC wire harness. Make sure the
wires are routed through all wiring retainers.
(7) Connect the wire harness to the blower motor,
blower motor resistor block, evaporator temperature
sensor and each actuator.
(8) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
INSTALLATION
WARNING: IF THE VEHICLE IS EQUIPPED WITH AIR
CONDITIONING, REVIEW THE WARNINGS AND
CAUTIONS IN PLUMBING BEFORE PERFORMING
THE FOLLOWING OPERATION. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - WARNING)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - CAUTION) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION -
REFRIGERANT HOSES/LINES/TUBES PRECAU-
TIONS)
(1) Position the HVAC housing into the vehicle. Be
certain that the evaporator condensate drain tube
and the housing mounting studs are inserted into
their correct locations.
(2) Install the two nuts that secure the HVAC
housing to the mounting studs in the passenger com-
partment. Tighten the nuts to 6.2 N´m (55 in. lbs.).
(3) Install the bolt that secures the HVAC housing
to the floor bracket in the passenger compartment.
Tighten the bolt to 6.2 N´m (55 in. lbs.).
(4) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL - INSTALLATION).
(5) Install the two nuts that secure the HVAC
housing to the mounting studs in the engine com-
partment. Tighten the nuts to 6.2 N´m (55 in. lbs.).
(6) Install the powertrain control module (PCM)
(Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/POWERTRAIN CONTROL MOD-
ULE - INSTALLATION).
(7) Unplug or remove the tape from the heater
core tubes and connect the heater hoses to the heater
core tubes.
(8) Unplug or remove the tape from the opened
refrigerant line fittings and the evaporator outlet
tube and install the accumulator (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/AC-
CUMULATOR - INSTALLATION).
(9) Unplug or remove the tape from the liquid line
and the evaporator inlet tube fittings. Connect the
liquid line coupler to the evaporator inlet tube (Referto 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - STANDARD PROCEDURE - A/C LINE COU-
PLERS).
(10) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(11) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
(12) Fill the engine cooling system (Refer to 7 -
COOLING/ENGINE - STANDARD PROCEDURE).
(13) Connect the battery negative cable.
(14) Start the engine and check for proper opera-
tion of the heating and air conditioning systems.
INSTRUMENT PANEL
DEMISTER DUCTS
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Remove the defroster ducts (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - REMOVAL).
(2) Remove the two screws that secure the center
distribution duct to the instrument panel support.
(3) Remove the center distribution duct from
instrument panel support, panel ducts and demister
ducts.
(4) Remove the right side panel duct adapter (Fig.
11).
(5) Remove the right side intermediate demister
duct.
(6) Remove the left side intermediate demister
duct.
(7) Remove the left side panel duct adapter.
(8) Remove the instrument panel cover (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - REMOVAL).
24 - 36 DISTRIBUTIONDR
HVAC HOUSING (Continued)

DEPLOYMENT - STANDARD
PROCEDURE, SERVICE AFTER A
SUPPLEMENTAL RESTRAINT............8O-7
DETECTION ASSY - DESCRIPTION,
NATURAL VAC LEAK..................25-23
DETECTION ASSY - INSTALLATION,
NATURAL VAC LEAK..................25-25
DETECTION ASSY - OPERATION,
NATURAL VAC LEAK..................25-23
DETECTION ASSY - REMOVAL, NATURAL
VAC LEAK..........................25-24
DETECTION PUMP - DESCRIPTION, LEAK . 25-13
DETECTION PUMP - INSTALLATION,
LEAK..............................25-16
DETECTION PUMP - OPERATION, LEAK . . . 25-14
DETECTION PUMP - REMOVAL, LEAK....25-16
DEVICES - STANDARD PROCEDURE,
ELECTROSTATIC DISCHARGE (ESD)
SENSITIVE........................8W-01-8
DIAGNOSTIC TROUBLE CODES -
DESCRIPTION........................25-1
DIAGNOSTICS (OBD) - DIAGNOSIS AND
TESTING, ON-BOARD...................7-5
DIAGRAMS - DESCRIPTION, HOW TO
USE WIRING......................8W-01-1
DIAGRAMS - HYDRAULIC SCHEMATICS,
SCHEMATICS.................21-176,21-337
DIESEL - CLEANING, RADIATOR - 5.9L....7-56
DIESEL - CLEANING, RADIATOR FAN -
5.9L................................7-35
DIESEL - CLEANING, WATER PUMP -
5.9L................................7-62
DIESEL - DESCRIPTION.................14-62
DIESEL - DESCRIPTION, 5.9L............11-3
DIESEL - DESCRIPTION, BELT
TENSIONER - 5.9L.....................7-23
DIESEL - DESCRIPTION, COOLING
SYSTEM FLOW - 5.9L...................7-3
DIESEL - DESCRIPTION, ENGINE 5.9L....9-232
DIESEL - DESCRIPTION, ENGINE BLOCK
HEATER - 5.9L........................7-37
DIESEL - DESCRIPTION, ENGINE
COOLANT THERMOSTAT - 5.9L...........7-46
DIESEL - DESCRIPTION, FAN DRIVE
VISCOUS CLUTCH - 5.9L...............7-52
DIESEL - DESCRIPTION, RADIATOR -
5.9L................................7-56
DIESEL - DESCRIPTION, TRANS COOLER
- 5.9L..............................7-68
DIESEL - DESCRIPTION, WATER PUMP -
5.9L................................7-62
DIESEL - FUEL INJECTOR FIRING ORDER . 14-48
DIESEL - INSPECTION, RADIATOR - 5.9L . . . 7-56
DIESEL - INSPECTION, RADIATOR FAN -
5.9L................................7-35
DIESEL - INSPECTION, TAILPIPE - 5.9L . . . 11-10
DIESEL - INSPECTION, WATER PUMP -
5.9L................................7-62
DIESEL - INSTALLATION................11-8
DIESEL - INSTALLATION...............14-62
DIESEL - INSTALLATION.....19-26,19-31,19-42
DIESEL - INSTALLATION, BELT
TENSIONER - 5.9L.....................7-24
DIESEL - INSTALLATION, DRIVE BELT -
5.9L
................................7-29
DIESEL - INSTALLATION, ENGINE BLOCK
HEATER - 5.9L
........................7-38
DIESEL - INSTALLATION, ENGINE
COOLANT THERMOSTAT - 5.9L
...........7-47
DIESEL - INSTALLATION, EXCEPT
........14-19
DIESEL - INSTALLATION, MUFFLER -
5.9L
...............................11-10
DIESEL - INSTALLATION, RADIATOR -
5.9L
................................7-57
DIESEL - INSTALLATION, RADIATOR FAN
- 5.9L
..............................7-36
DIESEL - INSTALLATION, TAILPIPE - 5.9L
. 11-11
DIESEL - INSTALLATION, WATER PUMP -
5.9L
................................7-62
DIESEL - MAINTENANCE SCHEDULES,
24-VALVE CUMMINS TURBO
.............0-12
DIESEL - OPERATION, BELT TENSIONER
- 5.9L
..............................7-23
DIESEL - OPERATION, ENGINE BLOCK
HEATER - 5.9L
........................7-38
DIESEL - OPERATION, ENGINE COOLANT
THERMOSTAT - 5.9L
...................7-46DIESEL - OPERATION, FAN DRIVE
VISCOUS CLUTCH - 5.9L...............7-52
DIESEL - OPERATION, RADIATOR - 5.9L . . . 7-56
DIESEL - OPERATION, TRANS COOLER -
5.9L................................7-69
DIESEL - OPERATION, WATER PUMP -
5.9L................................7-62
DIESEL - REMOVAL....................11-7
DIESEL - REMOVAL...................14-62
DIESEL - REMOVAL.........19-25,19-30,19-41
DIESEL - REMOVAL, BELT TENSIONER -
5.9L................................7-23
DIESEL - REMOVAL, DRIVE BELT - 5.9L....7-29
DIESEL - REMOVAL, ENGINE BLOCK
HEATER - 5.9L........................7-38
DIESEL - REMOVAL, ENGINE COOLANT
THERMOSTAT - 5.9L...................7-47
DIESEL - REMOVAL, EXCEPT...........14-17
DIESEL - REMOVAL, MUFFLER - 5.9L.....11-10
DIESEL - REMOVAL, RADIATOR - 5.9L.....7-56
DIESEL - REMOVAL, RADIATOR FAN -
5.9L................................7-35
DIESEL - REMOVAL, TAILPIPE - 5.9L.....11-10
DIESEL - REMOVAL, WATER PUMP -
5.9L................................7-62
DIESEL - SPECIFICATIONS, 5.9L.........9-244
DIESEL - TORQUE, FUEL SYSTEM -
EXCEPT.............................14-3
DIESEL ENGINE - DESCRIPTION, FUEL
REQUIREMENTS.......................0-1
DIESEL ENGINE - DIAGNOSIS AND
TESTING............................11-5
DIESEL ENGINE - DIAGNOSIS AND
TESTING, COOLING SYSTEM.............7-7
DIESEL ENGINE - INSTALLATION........8R-17
DIESEL ENGINE - INSTALLATION, 5.9L . . . 24-54,
24-58,24-72
DIESEL ENGINE - INSTALLATION,
EXCEPT............................8R-17
DIESEL ENGINE - REMOVAL............8R-16
DIESEL ENGINE - REMOVAL, 5.9L . . 24-53,24-56,
24-70
DIESEL ENGINE - REMOVAL, EXCEPT....8R-15
DIESEL ENGINE - STANDARD
PROCEDURE, DRAINING COOLING
SYSTEM 5.9L........................7-18
DIESEL ENGINE - STANDARD
PROCEDURE, REFILLING COOLING
SYSTEM 5.9L........................7-19
DIESEL ENGINE - TORQUE, FUEL
SYSTEM............................14-48
DIESEL ENGINE, SPECIAL TOOLS - 5.9L . . 9-246
DIESEL ENGINES - DESCRIPTION,
ENGINE OIL...........................0-2
DIESEL FUEL SYSTEM - DESCRIPTION . . . 14-45
DIESEL FUEL SYSTEM, SPECIAL TOOLS . . 14-49
DIESEL ONLY - ASSEMBLY, 5.9L..........7-70
DIESEL ONLY - DISASSEMBLY, 5.9L.......7-70
DIFFERENTIAL - ASSEMBLY . . . 3-129,3-156,3-47,
3-73,3-99
DIFFERENTIAL - DISASSEMBLY....3-128,3-155,
3-47,3-72,3-98
DIFFERENTIAL - INSTALLATION....3-130,3-157,
3-48,3-74,3-99
DIFFERENTIAL - REMOVAL
. . . 3-127,3-155,3-46,
3-72,3-97
DIFFERENTIAL CASE BEARINGS -
INSTALLATION
....3-106,3-134,3-161,3-48,3-75
DIFFERENTIAL CASE BEARINGS -
REMOVAL
........3-105,3-134,3-161,3-48,3-75
DIFFERENTIAL COVER - INSTALLATION
....3-97
DIFFERENTIAL COVER - REMOVAL
........3-97
DIFFERENTIAL TRAC-RITE - ASSEMBLY
. . 3-133,
3-161
DIFFERENTIAL TRAC-RITE - CLEANING
. . . 3-132,
3-160
DIFFERENTIAL TRAC-RITE -
DESCRIPTION
..................3-131,3-158
DIFFERENTIAL TRAC-RITE -
DISASSEMBLY
..................3-131,3-158
DIFFERENTIAL TRAC-RITE - INSPECTION
. 3-132,
3-160
DIFFERENTIAL TRAC-RITE - OPERATION
. . 3-131,
3-158
DIFFERENTIAL-TRAC-LOK - ASSEMBLY
. . . 3-103
DIFFERENTIAL-TRAC-LOK -
DESCRIPTION
.......................3-100DIFFERENTIAL-TRAC-LOK - DIAGNOSIS
AND TESTING.......................3-100
DIFFERENTIAL-TRAC-LOK -
DISASSEMBLY.......................3-101
DIFFERENTIAL-TRAC-LOK - OPERATION . . . 3-100
DIMENSIONS - SPECIFICATIONS, BODY
OPENING...........................23-99
DIMENSIONS - SPECIFICATIONS, FRAME . . 13-16
DIODE - INSTALLATION............8W-01-14
DIODE - REMOVAL................8W-01-14
DIODE REPLACEMENT - STANDARD
PROCEDURE........................24-45
DISC - INSTALLATION, CLUTCH...........6-5
DISC - REMOVAL, CLUTCH...............6-5
DISC BRAKE CALIPER ADAPTER MOUNT
- INSTALLATION......................5-22
DISC BRAKE CALIPERS - DESCRIPTION....5-16
DISC BRAKE CALIPERS - OPERATION.....5-16
DISC BRAKE ROTOR, DIAGNOSIS AND
TESTING............................5-32
DISCHARGE (ESD) SENSITIVE DEVICES -
STANDARD PROCEDURE,
ELECTROSTATIC...................8W-01-8
DISCHARGE LINE - DESCRIPTION, A/C....24-56
DISPLAY TEST MODE - DESCRIPTION,
STATE ..............................25-1
DISTRIBUTION - DESCRIPTION, POWER . 8W-97-1
DISTRIBUTION - OPERATION, POWER . . 8W-97-1
DISTRIBUTION DUCT - INSTALLATION,
FLOOR.............................24-34
DISTRIBUTION DUCT - REMOVAL,
FLOOR.............................24-33
DISTRIBUTION SYSTEMS, SPECIAL
TOOLS - POWER...................8W-97-2
DOME LAMP - DESCRIPTION...........8L-26
DOME LAMP - INSTALLATION..........8L-26
DOME LAMP - OPERATION.............8L-26
DOME LAMP - REMOVAL..............8L-26
DOOR - INSTALLATION...........23-18,23-28
DOOR - INSTALLATION, BLEND.........24-27
DOOR - INSTALLATION, DEFROST.......24-31
DOOR - INSTALLATION, FUEL FILL.......23-39
DOOR - INSTALLATION, MODE..........24-38
DOOR - INSTALLATION, RECIRCULATION . . 24-40
DOOR - REMOVAL...............23-18,23-28
DOOR - REMOVAL, BLEND.............24-27
DOOR - REMOVAL, DEFROST...........24-31
DOOR - REMOVAL, FUEL FILL..........23-39
DOOR - REMOVAL, MODE..............24-38
DOOR - REMOVAL, RECIRCULATION.....24-39
DOOR ACTUATOR - DESCRIPTION,
BLEND.............................24-17
DOOR ACTUATOR - DESCRIPTION,
DEFROST...........................24-20
DOOR ACTUATOR - DESCRIPTION,
MODE.............................24-23
DOOR ACTUATOR - DESCRIPTION,
RECIRCULATION.....................24-24
DOOR ACTUATOR - INSTALLATION,
BLEND.............................24-18
DOOR ACTUATOR - INSTALLATION,
DEFROST...........................24-21
DOOR ACTUATOR - INSTALLATION,
MODE.............................24-23
DOOR ACTUATOR - INSTALLATION,
RECIRCULATION.....................24-25
DOOR ACTUATOR - OPERATION, BLEND . . 24-17
DOOR ACTUATOR - OPERATION,
DEFROST...........................24-21
DOOR ACTUATOR - OPERATION, MODE . . . 24-23
DOOR ACTUATOR - OPERATION,
RECIRCULATION
.....................24-24
DOOR ACTUATOR - REMOVAL, BLEND
....24-17
DOOR ACTUATOR - REMOVAL, DEFROST
. . 24-21
DOOR ACTUATOR - REMOVAL, MODE
....24-23
DOOR ACTUATOR - REMOVAL,
RECIRCULATION
.....................24-24
DOOR AJAR INDICATOR - DESCRIPTION
. . 8J-23
DOOR AJAR INDICATOR - OPERATION
....8J-23
DOOR AJAR SWITCH - DESCRIPTION
....8L-27
DOOR AJAR SWITCH - OPERATION
......8L-27
DOOR GLASS - INSTALLATION
.....23-20,23-30
DOOR GLASS - REMOVAL
........23-20,23-30
DOOR GLASS RUN WEATHERSTRIP -
INSTALLATION, FRONT
................23-92
DOOR GLASS RUN WEATHERSTRIP -
INSTALLATION, REAR
.................23-93
10 INDEXDR
Description Group-Page Description Group-Page Description Group-Page