1998 DODGE RAM 1500 harness

SPLICE
NUMBERLOCATION FIG.
S122 Left Front Fender 22
S123 Left Front Fender 22, 23
S124 Center Rear of Engine Compartment N/S
S125 Right Rear of Engine Compartment 4, 8
S130 Top Front of Transmission 3, 9
S132 Left Rear of Engine Compartment 3, 9
S133 Left Rear of Engine 4, 9
S134 Left Rear of Engine Compartment 3, 9
S135 Headlamp and Dash, Left Side N/S
S136 Left Front Fender 23
S137 Left Rear of Engine Compartment 21
S138 Left Rear of Engine N/S
S139 Right Front of Transmission N/S
S140 Right Rear Engine Compartment 22
S142 Left Side of Engine 3
S143 Left Side of Engine Compartment N/S
S144 Top Front of Transmission N/S
S145 Left Front Fender 23
S148 Top Front of Transmission 3
S149 Left Rear of Engine 6
S150 Top Center of Engine 3, 9
S153 Rear Engine Compartment N/S
S154 Left Top Engine N/S
S155 Left Rear Engine Compartment near T/O for Fuel Control Actuator 9
S157 Near T/O for Camshaft Position Sensor N/S
S158 Near T/O for C114 10
S159 Near T/O for Engine Control Module N/S
S160 Top Left Engine 10
S162 Left Side Engine N/S
S163 Right Side Engine N/S
S164 Near Engine Control Module C2 10
S165 Near Engine Control Module C2 10
S166 In Battery Positive Harness N/S
S168 Right Rear of Engine 3
S169 Right Rear of Engine 3, 7
S170 Left Engine 10
S171 Top Left Engine 10
S172 In T/O for Fuel Control Actuator N/S
S173 Near T/O for Engine Control Module N/S
S174 Near T/O for C114 N/S
S175 Near T/O for Engine Control Module N/S
8W - 91 - 10 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

SPECIAL TOOLS
POWER DISTRIBUTION SYSTEMS
CIGAR LIGHTER OUTLET
DESCRIPTION
On models equipped a cigar lighter outlet is
installed to the left of the center stack area in the
lower instrument panel. The cigar lighter outlet is
secured by a snap fit within the bezel.
The cigar lighter outlet, plastic cap and the knob
and heating element unit are available for service
replacement. These components cannot be repaired
and, if faulty or damaged, they must be replaced.
OPERATION
The cigar lighter consists of two major components:
a knob and heating element unit, and the cigar
lighter base or outlet shell. The receptacle shell is
connected to ground, and an insulated contact in the
bottom of the shell is connected to battery current.
The cigar lighter receives battery voltage from a fuse
in the junction block when the ignition switch is in
the Accessory or Run positions.
The cigar lighter knob and heating element are
encased within a spring-loaded housing, which also
features a sliding protective heat shield. When the
knob and heating element are inserted in the outlet
shell, the heating element resistor coil is grounded
through its housing to the outlet shell. If the cigar
lighter knob is pushed inward, the heat shield slides
up toward the knob exposing the heating element,
and the heating element extends from the housing
toward the insulated contact in the bottom of the
outlet shell.
Two small spring-clip retainers are located on
either side of the insulated contact inside the bottom
of the outlet shell. These clips engage and hold the
heating element against the insulated contact longenough for the resistor coil to heat up. When the
heating element is engaged with the contact, battery
current can flow through the resistor coil to ground,
causing the resistor coil to heat.
When the resistor coil becomes sufficiently heated,
excess heat radiates from the heating element caus-
ing the spring-clips to expand. Once the spring-clips
expand far enough to release the heating element,
the spring-loaded housing forces the knob and heat-
ing element to pop back outward to their relaxed
position. When the cigar lighter knob and element
are pulled out of the outlet shell, the protective heat
shield slides downward on the housing so that the
heating element is recessed and shielded around its
circumference for safety.
DIAGNOSIS AND TESTING - CIGAR LIGHTER
OUTLET
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Check the fused B(+) fuse in the integrated
power module. If OK, go to Step 2. If not OK, repair
the shorted circuit or component as required and
replace the faulty fuse.
(2) Turn the ignition switch to the Run position.
Check for battery voltage at the fused B(+) fuse in
the integrated power module. If OK, go to Step 3. If
not OK, repair the open or short as required.
(3) Remove the cigar lighter knob and element
from the cigar lighter outlet shell. Check for continu-
ity between the inside circumference of the cigar
lighter outlet shell and a good ground. there should
be continuity. If OK, go to Step 4. If not OK, go to
Step 5.
(4) Turn the ignition switch to the Run position.
Check for battery voltage at the insulated contact
located at the back of the cigar lighter outlet shell. If
OK, replace the faulty cigar lighter knob and ele-
ment. If not OK, go to Step 5.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Check for continuity between the ground circuit cav-
ity of the cigar lighter wire harness connector and a
good ground. There should be continuity. If OK, go to
Step 6. If not OK, repair the open ground circuit to
ground as required.
(6) Connect the battery negative cable. Turn the
ignition switch to the Accessory or Run positions.
Check for battery voltage at the fused B(+) circuit
cavity of the cigar lighter wire harness connector. If
OK, replace the faulty cigar lighter outlet. If not OK,
repair the open fused B(+) circuit to the integrated
power module fuse as required.Terminal Pick Kit 6680
8W - 97 - 2 8W-97 POWER DISTRIBUTIONDR
POWER DISTRIBUTION (Continued)

requires the use of a DRB IIItscan tool and the
proper Body Diagnostic Procedures manual.
Before any testing of the front control module is
attempted, the battery should be fully charged and
all wire harness and ground connections inspected
around the affected areas on the vehicle.
REMOVAL
(1) Disconnect the positive and negative battery
cables from the battery.
(2) Partially remove the integrated power module
from the engine compartment (Refer to 8 - ELECTRI-
CAL/POWER DISTRIBUTION/INTEGRATED
POWER MODULE - REMOVAL).
(3) Remove the front control module retaining
screws.
(4) Using both hands, pull the front control module
straightfrom the integrated power module assembly
to disconnect the 49-way electrical connector and
remove the front control module from the vehicle.
INSTALLATION
(1) Install the front control module on the inte-
grated power module assembly by pushing the
49-way electrical connector straight in.
(2) Install the front control module retaining
screws. Torque the screws to 7 in. lbs.
(3) Install the integrated power module (Refer to 8
- ELECTRICAL/POWER DISTRIBUTION/INTE-
GRATED POWER MODULE - INSTALLATION).
(4) Connect the positive and negative battery
cables.
IOD FUSE
DESCRIPTION
All vehicles are equipped with an Ignition-Off
Draw (IOD) fuse that is disconnected within the Inte-
grated Power Module when the vehicle is shipped
from the factory. Dealer personnel are to reconnect
the IOD fuse in the Integrated Power Module as part
of the preparation procedures performed just prior to
new vehicle delivery.
A laser printed fuse layout map is integral to the
Integrated Power Module cover to ensure proper fuse
identification. The IOD fuse is a 20 ampere mini
blade-type fuse, located in fuse cavity # 51 (Fig. 6).
The fuse is secured within a black molded plastic
fuse holder and puller unit that serves both as a tool
for disconnecting and reconnecting the fuse in its
Integrated Power Module cavity, and as a fuse holder
that conveniently stores the fuse in the same Inte-
grated Power Module cavity after it has been discon-
nected.
CIRCUITS INCLUDED WITH IOD FUSE
²Cluster (CCN)
²Diagnostic Connector
²Map Lamps
²Glove Box Lamp
²Courtesy Lamps
²Radio
²Underhood Lamp
OPERATION
The term ignition-off draw identifies a normal con-
dition where power is being drained from the battery
with the ignition switch in the Off position. The IOD
fuse feeds the memory and sleep mode functions for
some of the electronic modules in the vehicle as well
as various other accessories that require battery cur-
rent when the ignition switch is in the Off position.
The only reason the IOD fuse is disconnected is to
reduce the normal IOD of the vehicle electrical sys-
tem during new vehicle transportation and pre-deliv-
ery storage to reduce battery depletion, while still
allowing vehicle operation so that the vehicle can be
loaded, unloaded and moved as needed by both vehi-
cle transportation company and dealer personnel.
The IOD fuse is disconnected from Integrated
Power Module fuse cavity # 51 when the vehicle is
shipped from the assembly plant. Dealer personnel
must reconnect the IOD fuse when the vehicle is
being prepared for delivery in order to restore full
electrical system operation. Once the vehicle is pre-
pared for delivery, the IOD function of this fuse
Fig. 6 IOD FUSE LOCATION
1 - IOD FUSE
8W - 97 - 6 8W-97 POWER DISTRIBUTIONDR
FRONT CONTROL MODULE (Continued)

becomes transparent and the fuse that has been
assigned the IOD designation becomes only another
Fused B(+) circuit fuse.
The IOD fuse can be used by the vehicle owner as
a convenient means of reducing battery depletion
when a vehicle is to be stored for periods not to
exceed about thirty days. However, it must be
remembered that disconnecting the IOD fuse will not
eliminate IOD, but only reduce this normal condition.
If a vehicle will be stored for more than about thirty
days, the battery negative cable should be discon-
nected to eliminate normal IOD; and, the battery
should be tested and recharged at regular intervals
during the vehicle storage period to prevent the bat-
tery from becoming discharged or damaged.
REMOVAL
The Ignition-Off Draw (IOD) fuse is disconnected
from Integrated Power Module fuse cavity # 51 when
the vehicle is shipped from the assembly plant.
Dealer personnel must reconnect the IOD fuse when
the vehicle is being prepared for delivery in order to
restore full electrical system operation.
(1) Turn the ignition switch to the Off position.
(2) Remove the Integrated Power Module cover.
(3) Grasp the outer tabs of the IOD fuse holder
unit in fuse cavity # 51 between the thumb and fore-
finger and pull the unit firmly upward.
(4) Install the Integrated Power Module cover.
INSTALLATION
(1) Turn the ignition switch to the Off position.
(2) Remove the Integrated Power Module cover.
(3) To install the IOD fuse, use a thumb to press
the IOD fuse holder unit in fuse cavity # 51 firmly
into the Integrated Power Module.
(4) Install the Integrated Power Module cover.
POWER OUTLET
DESCRIPTION
Two power outlets are utilized on this model. One
in the instrument panel center lower bezel and the
other in the center console. The power outlet bases
are secured by a snap fit within the instrument
panel or trim panel. A plastic protective cap snaps
into the power outlet base when the power outlet is
not being used, and hangs from the power outlet base
mount by an integral bail strap while the power out-
let is in use.The power outlet receptacle unit and the accessory
power outlet protective cap are available for service.
The power outlet receptacle cannot be repaired and,
if faulty or damaged, it must be replaced.
OPERATION
The power outlet base or receptacle shell is con-
nected to ground, and an insulated contact in the
bottom of the shell is connected to battery current.
The power outlet receives battery voltage from a fuse
in the integrated power module at all times.
While the power outlet is very similar to a cigar
lighter base unit, it does not include the two small
spring-clip retainers inside the bottom of the recepta-
cle shell that are used to secure the cigar lighter
heating element to the insulated contact.
DIAGNOSIS AND TESTING - POWER OUTLET
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Check the fused B(+) fuse in the integrated
power module. If OK, go to Step 2. If not OK, repair
the shorted circuit or component as required and
replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the integrated power module. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit to the
battery as required.
(3) Remove the plastic protective cap from the
power outlet receptacle. Check for continuity between
the inside circumference of the power outlet recepta-
cle and a good ground. There should be continuity. If
OK, go to Step 4. If not OK, go to Step 5.
(4) Check for battery voltage at the insulated con-
tact located at the back of the power outlet recepta-
cle. If not OK, go to Step 5.
(5) Disconnect and isolate the battery negative
cable. Remove the power outlet receptacle from the
instrument panel. Disconnect the wire harness con-
nector from the power outlet receptacle. Check for
continuity between the ground circuit cavity of the
power outlet wire harness connector and a good
ground. There should be continuity. If OK, go to Step
6. If not OK, repair the open ground circuit to ground
as required.
(6) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
power outlet wire harness connector. If OK, replace
the faulty power outlet receptacle. If not OK, repair
the open fused B(+) circuit to the integrated power
module fuse as required.
DR8W-97 POWER DISTRIBUTION 8W - 97 - 7
IOD FUSE (Continued)

REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Pull the cigar lighter knob and element out of
the cigar lighter receptacle base, or unsnap the pro-
tective cap from the power outlet receptacle base.
(3) Look inside the cigar lighter or power outlet
receptacle base and note the position of the rectangu-
lar retaining bosses of the mount that secures the
receptacle base to the panel (Fig. 7).
(4) Insert a pair of external snap ring pliers into
the cigar lighter or power outlet receptacle base and
engage the tips of the pliers with the retaining
bosses of the mount.
(5) Squeeze the pliers to disengage the mount
retaining bosses from the receptacle base and, using
a gentle rocking motion, pull the pliers and the
receptacle base out of the mount.
(6) Pull the receptacle base away from the instru-
ment panel far enough to access the instrument
panel wire harness connector.
(7) Disconnect the instrument panel wire harness
connector from the cigar lighter or power outlet
receptacle base connector receptacle.
(8) Remove the cigar lighter or power outlet mount
from the instrument panel.
INSTALLATION
(1) Reconnect the instrument panel wire harness
connector to the cigar lighter or power outlet recep-
tacle base connector receptacle.
(2) Install the cigar lighter or power outlet mount
into the instrument panel.
(3) Align the splines on the outside of the cigar
lighter or power outlet receptacle base connector
receptacle with the grooves on the inside of the
mount.
(4) Press firmly on the cigar lighter or power out-
let receptacle base until the retaining bosses of the
mount are fully engaged in their receptacles.(5) Install the cigar lighter knob and element into
the cigar lighter receptacle base, or the protective cap
into the power outlet receptacle base.
(6) Reconnect the battery negative cable.
Fig. 7 Cigar Lighter and Power Outlet Remove/
Install
1 - KNOB AND ELEMENT
2 - RETAINING BOSSES-ENGAGE PLIERS HERE
3 - BASE
4 - PARTIALLY REMOVED
5 - EXTERNAL SNAP-RING PLIERS
6 - MOUNT
7 - BASE
8W - 97 - 8 8W-97 POWER DISTRIBUTIONDR
POWER OUTLET (Continued)

(12) Disconnect heater hoses from heater core and
remove hose assembly.
(13) Disconnect throttle and speed control cables.
(14) Remove upper radiator hose from engine.
(15) Remove lower radiator hose from engine.
(16) Remove radiator/cooling module assembly.
(17) Disconnect the engine to body ground straps
at the left side of cowl.
(18) Disconnect the engine wiring harness at the
following points:
²Intake air temperature (IAT) sensor
²Fuel Injectors
²Throttle Position (TPS) Switch
²Idle Air Control (IAC) Motor
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold Absolute Pressure MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
²Crankshaft Position Sensor
(19) Remove coil over plugs.
(20) Release fuel rail pressure.
(21) Remove fuel rail and secure away from
engine.
NOTE: It is not necessary to release the quick con-
nect fitting from the fuel supply line for engine
removal.
(22) Remove the PCV hose.
(23) Remove the breather hoses.
(24) Remove the vacuum hose for the power brake
booster.
(25) Disconnect knock sensors.
(26) Remove engine oil dipstick tube.
(27) Remove intake manifold.
(28) Install engine lifting fixture,special tool#8247,
using original fasteners from the removed intake
manifold, and fuel rail. Torque to factory specifica-
tions.
NOTE: Recheck bolt torque for engine lift plate
before removing engine.
(29) Secure the left and right engine wiring har-
nesses away from engine.
(30) Raise vehicle.
(31) Disconnect oxygen sensor wiring.
(32) Disconnect crankshaft postion sensor.
(33) Disconnect the engine block heater power
cable, if equipped.
(34) Disconnect the front propshaft at the front
differential and secure out of way.
NOTE: It is necessary to disconnect the front prop-
shaft for access to the starter and left side exhaust
flange.(35) Remove the starter.
(36) Remove the ground straps from the left and
right side of the block.
(37) Disconnect the right and left exhaust pipes at
the manifolds and from the crossover, and remove
from the vehicle.
NOTE: The exhaust clamps at the manifolds cannot
be reused. New clamps must be used or leaks may
occur.
(38) Remove the structural cover.
(39) Remove torque convertor bolts, and mark
location for reassembly.
(40) Remove transmission bellhousing to engine
bolts.
(41) Remove left and right engine mount thru
bolts.
(42) Lower the vehicle.
(43) Support the transmission with a suitable jack.
(44) Connect a suitable engine hoist to the engine
lift plate.
(45) Remove engine from vehicle.
INSTALLATION
(1) Position the engine in the vehicle.
(2) Install both left and right side engine mounts
onto engine.
(3) Raise the vehicle.
(4) Install the transmission bellhousing to engine
mounting bolts. Tighten the bolts to 41 N´m (30ft.
lbs.).
(5) Tighten the engine mount thru bolts.
(6) Install the torque convertor bolts.
(7) Connect the ground straps on the left and right
side of the engine.
(8) Install the starter.
(9) Connect the crankshaft position sensor.
(10) Install the engine block heater power cable, if
equipped.
CAUTION: The structural cover requires a specific
torque sequence. Failure to follow this sequence
may cause severe damage to the cover.
(11) Install the structural cover.
NOTE: New clamps must be used on exhaust man-
ifold flanges. Failure to use new clamps may result
in exhaust leaks.
(12) Install the left and right exhaust pipes.
(13) Connect the left and right oxygen sensors.
(14) Lower vehicle.
(15) Remove the engine lift plate.
(16) Connect the knock sensors.
DRENGINE - 3.7L 9 - 11
ENGINE - 3.7L (Continued)

(17) Connect the engine to body ground straps at
the left side of the cowl.
(18) Install the intake manifold.
(19) Install the engine oil dipstick tube.
(20) Install the power brake booster vacuum hose.
(21) Install the breather hoses.
(22) Install the PCV hose.
(23) Install the fuel rail.
(24) Install the coil over plugs.
(25) Connect the engine wiring harness at the fol-
lowing points:
²Intake air temperature (IAT) sensor
²Fuel Injectors
²Throttle Position (TPS) Switch
²Idle Air Control (IAC) Motor
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold Absolute Pressure MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
²Crankshaft Position Sensor
(26) Reinstall the radiator/cooling module assem-
bly.
(27) Connect lower radiator hose.
(28) Connect upper radiator hose.
(29) Connect throttle and speed control cables.
(30) Install the heater hose assembly.
(31) Install coolant recovery bottle.
(32) Install the power steering pump.
(33) Install the generator.
(34) Install the A/C compressor.
(35) Install the drive belt.
(36) Install the fan shroud with the viscous fan
assembly.
(37) Install the radiator core support bracket.
(38) Install the air cleaner assembly.
(39) Refill the engine cooling system.
(40) Recharge the air conditioning.
(41) Install the hood.
(42) Check and fill engine oil.
(43) Connect the battery negative cable.
(44) Start the engine and check for leaks.SPECIFICATIONS
SPECIFICATIONS - 3.7L ENGINE
GENERAL SPECIFICATIONS
DESCRIPTION SPECIFICATION
Type 90É SOHC V6 12 Valve
Number of
Cylinders4
Firing Order 1-6-5-4-3-2
Lead Cylinder No. 1 Left Bank
Compression
Ratio9.1:1
Max. Variation
Between
Cylinders25%
Metric Standard
Displacement 3.7 Liters 226 Cubic
Inches
Bore 93.0 mm 3.66 in.
Stroke 90.8 mm 3.40 in.
Horsepower 210@5200 RPM
Torque 225ft. lbs.@4200 PRM
Compression
Pressure1172-1551 kPa 170-225 psi
CYLINDER BLOCK
DESCRIPTION SPECIFICATION
Metric Standard
Bore Diameter 93.0   .0075
mm3.6619   0.0003
in.
Out of Round
(MAX)0.076 mm 0.003 in.
Taper (MAX) 0.051 mm 0.002 in.
9 - 12 ENGINE - 3.7LDR
ENGINE - 3.7L (Continued)

REMOVAL
(1) Disconnect negative cable from battery.
(2)
Remove the resonator assemble and air inlet hose.
(3) Disconnect injector connectors and un-clip the
injector harness.
(4) Route injector harness in front of cylinder head
cover.
(5) Disconnect the left side breather tube and
remove the breather tube.
(6) Remove the cylinder head cover mounting bolts
(Fig. 16).
(7) Remove cylinder head cover and gasket.
NOTE: The gasket may be used again, providing no
cuts, tears, or deformation has occurred.
INSTALLATION
CAUTION: Do not use harsh cleaners to clean the
cylinder head covers. Severe damage to covers
may occur.
NOTE: The gasket may be used again, provided no
cuts, tears, or deformation has occurred.
(1) Clean cylinder head cover and both sealing sur-
faces. Inspect and replace gasket as necessary.
(2) Tighten cylinder head cover bolts and double
ended studs to 12 N´m (105 in. lbs.).(3) Install left side breather and connect breather
tube.
(4) Connect injector electrical connectors and injec-
tor harness retaining clips.
(5) Install the resonator and air inlet hose.
(6) Connect negative cable to battery.
INTAKE/EXHAUST VALVES &
SEATS
DESCRIPTION
The valves are made of heat resistant steel and
have chrome plated stems to prevent scuffing. Each
valve is actuated by a roller rocker arm which pivots
on a stationary lash adjuster. All valves use three
bead lock keepers to retain the springs and promote
valve rotation.
STANDARD PROCEDURE - REFACING
NOTE: Valve seats that are worn or burned can be
reworked, provided that correct angle and seat
width are maintained. Otherwise the cylinder head
must be replaced.
NOTE: When refacing valves and valve seats, it is
important that the correct size valve guide pilot be
used for reseating stones. A true and complete sur-
face must be obtained.
(1) Using a suitable dial indicator measure the
center of the valve seat Total run out must not
exceed 0.051 mm (0.002 in).
(2) Apply a small amount of Prussian blue to the
valve seat, insert the valve into the cylinder head,
while applying light pressure on the valve rotate the
valve. Remove the valve and examine the valve face.
If the blue is transferred below the top edge of the
valve face, lower the valve seat using a 15 degree
stone. If the blue is transferred to the bottom edge of
the valve face, raise the valve seat using a 65 degree
stone.
(3) When the seat is properly positioned the width
of the intake seat must be 1.75 - 2.36 mm (0.0689 -
0.0928 in.) and the exhaust seat must be 1.71 - 2.32
mm (0.0673 - 0.0911 in.).
(4) Check the valve spring installed height after
refacing the valve and seat. The installed height for
both intake and exhaust valve springs must not
exceed 40.74 mm (1.6039 in.).
Fig. 16 CYLINDER HEAD COVER - TYPICAL
1 - SCREWS
2 - CYLINDER HEAD COVER
9 - 28 ENGINE - 3.7LDR
CYLINDER HEAD COVER(S) (Continued)