1998 DODGE RAM 1500 body control module

(2) From the underside of the cowl plenum cover/
grille panel, reconnect the cowl plenum and washer
nozzle hoses to the three barbed nipples of the check
valve.
(3) Reinstall the cowl plenum cover/grille panel
over the cowl plenum. (Refer to 23 - BODY/EXTERI-
OR/COWL GRILLE - INSTALLATION).
(4) Close and latch the hood.
(5) Reinstall both wiper arms onto the wiper piv-
ots. (Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER ARM - INSTALLATION).
WASHER FLUID LEVEL
SWITCH
DESCRIPTION
The washer fluid level switch is a single pole, sin-
gle throw reed-type switch mounted on the outboard
side of the of the washer reservoir in the engine com-
partment (Fig. 6). Only the molded plastic switch
mounting flange and the integral connector recepta-
cle are visible when the switch is installed in the res-
ervoir. A short nipple formation extends from the
inner surface of the switch mounting flange, and a
barb on the nipple near the switch mounting flange
is pressed through a rubber grommet seal installed
in the mounting hole of the reservoir.
A small, molded plastic float has two pivot pins
near its center that are snapped into two receptacles
near the ends of two stanchions that extend toward
the float from the switch nipple formation. A small
magnet is secured within the end of the float nearestthe switch nipple formation, and a reed switch is con-
cealed within the nipple. A diagnostic resistor is con-
nected between the two switch terminals within the
switch mounting flange. The washer fluid level
switch cannot be adjusted or repaired. If faulty or
damaged, the switch must be replaced.
OPERATION
The washer fluid level switch uses a pivoting,
oblong float to monitor the level of the washer fluid
in the washer reservoir. The float contains a small
magnet. When the float pivots, the proximity of this
magnet to a stationary reed switch within the nipple
formation of the switch changes. When the fluid level
in the washer reservoir is at or above the float level,
the float moves to a vertical position, the influence of
the float magnetic field is removed from the reed
switch, and the normally open reed switch contacts
open. When the fluid level in the washer reservoir
falls below the level of the pivoting float, the float
moves to a horizontal position, the influence of the
float magnetic field is applied to the reed switch, and
the contacts of the normally open reed switch close.
The washer fluid level switch is connected to the
vehicle electrical system through a dedicated take
out and connector of the right (except diesel engines)
or left (diesel engines only) headlamp and dash wire
harness. The switch is connected in series between a
clean ground output of the Front Control Module
Fig. 5 Check Valve Remove/Install
1 - WASHER NOZZLE HOSE (RIGHT)
2 - CHECK VALVE
3 - ROUTING CLIP
4 - COWL PLENUM WASHER HOSE
5 - COWL PLENUM COVER/GRILLE PANEL (UNDERSIDE)
6 - WASHER NOZZLE HOSE (LEFT)
Fig. 6 Washer Fluid Level Switch
1 - MOUNTING FLANGE
2 - BARBED NIPPLE
3 - FLOAT
4 - RESERVOIR
5 - GROMMET SEAL
6 - PIVOT
7 - MAGNET
8 - CONNECTOR RECEPTACLE
DRWIPERS/WASHERS 8R - 9
CHECK VALVE (Continued)

OPERATION
The wiper module operation is controlled by the
battery current inputs received by the wiper motor
through the wiper on/off and wiper high/low relays.
The wiper motor speed is controlled by current flow
to either the low speed or the high speed set of
brushes. The park switch is a single pole, single
throw, momentary switch within the wiper motor
that is mechanically actuated by the wiper motor
transmission components. The park switch alter-
nately opens and closes the wiper park switch sense
circuit to ground, depending upon the position of the
wipers on the glass. This feature allows the motor to
complete its current wipe cycle after the wiper sys-
tem has been turned Off, and to park the wiper
blades in the lowest portion of the wipe pattern. The
automatic resetting circuit breaker protects the
motor from overloads. The wiper motor crank arm,
the two wiper linkage members, and the two wiper
pivots mechanically convert the rotary output of the
wiper motor to the back and forth wiping motion of
the wiper arms and blades on the glass.
REMOVAL
(1) Remove both wiper arms from the wiper pivots.
(Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER ARM - REMOVAL).
(2) Unlatch and open the hood.
(3) Disconnect and isolate the battery negative
cable.
(4) Remove the cowl plenum cover/grille panel
from over the cowl plenum. (Refer to 23 - BODY/EX-
TERIOR/COWL GRILLE - REMOVAL).
(5) Disconnect the left headlamp and dash wire
harness connector for the wiper motor from the
motor pigtail wire connector (Fig. 26).(6) Remove the two screws that secure the wiper
module to the top of the cowl plenum panel at the
pivot brackets.
(7) Remove the two screws that secure the wiper
module to the bottom of the cowl plenum panel.
(8) Remove the wiper module from the cowl ple-
num panel as a unit.
INSTALLATION
(1) Position the wiper module into the cowl ple-
num as a unit (Fig. 26).
(2) Install the two screws that secure the wiper
module to the top of the cowl plenum panel at the
pivot brackets. Tighten the screw on the driver side,
followed by the screw on the passenger side. Tighten
the screws to 7 N´m (60 in. lbs.).
(3) Install and tighten the screws that secure the
wiper module to the bottom of the cowl plenum
panel. Tighten the screw on the passenger side, fol-
lowed by the screw on the driver side. Tighten the
screws to 7 N´m (60 in. lbs.).
(4) Reconnect the left headlamp and dash wire
harness connector for the wiper motor to the motor
pigtail wire connector.
(5) Reinstall the cowl plenum cover/grille panel
over the cowl plenum. (Refer to 23 - BODY/EXTERI-
OR/COWL GRILLE - INSTALLATION).
(6) Reconnect the battery negative cable.
(7) Close and latch the hood.
(8) Reinstall both wiper arms onto the wiper piv-
ots. (Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER ARMS - INSTALLATION).
DRWIPERS/WASHERS 8R - 23
WIPER MODULE (Continued)

DESCRIPTION - CIRCUIT FUNCTIONS
All circuits in the diagrams use an alpha/numeric
code to identify the wire and it's function. To identify
which circuit code applies to a system, refer to the
Circuit Identification Code Chart. This chart shows
the main circuits only and does not show the second-
ary codes that may apply to some models.
CIRCUIT IDENTIFICATION CODE CHART
CIRCUIT FUNCTION
A BATTERY FEED
B BRAKE CONTROLS
C CLIMATE CONTROLS
D DIAGNOSTIC CIRCUITS
E DIMMING ILLUMINATION
CIRCUITS
F FUSED CIRCUITS
G MONITORING CIRCUITS
(GAUGES)
H OPEN
I NOT USED
J OPEN
K POWERTRAIN CONTROL
MODULE
L EXTERIOR LIGHTING
M INTERIOR LIGHTING
N NOT USED
O NOT USED
P POWER OPTION (BATTERY
FEED)
Q POWER OPTIONS (IGNITION
FEED)
R PASSIVE RESTRAINT
S SUSPENSION/STEERING
T TRANSMISSION/TRANSAXLE/
TRANSFER CASE
U OPEN
V SPEED CONTROL, WIPER/
WASHER
W OPEN
X AUDIO SYSTEMS
Y OPEN
Z GROUNDS
DESCRIPTION - SECTION IDENTIFICATION AND
INFORMATION
The wiring diagrams are grouped into individual
sections. If a component is most likely found in a par-
ticular group, it will be shown complete (all wires,
connectors, and pins) within that group. For exam-
ple, the Auto Shutdown Relay is most likely to be
found in Group 30, so it is shown there complete. It
can, however, be shown partially in another group if
it contains some associated wiring.
Splice diagrams in Section 8W-70 show the entire
splice and provide references to other sections the
splices serves. Section 8W-70 only contains splice dia-
grams that are not shown in their entirety some-
where else in the wiring diagrams.
Section 8W-80 shows each connector and the cir-
cuits involved with that connector. The connectors
are identified using the name/number on the dia-
gram pages.
WIRING SECTION CHART
GROUP TOPIC
8W-01 thru
8W-09General information and Diagram
Overview
8W-10 thru
8W-19Main Sources of Power and
Vehicle Grounding
8W-20 thru
8W-29Starting and Charging
8W-30 thru
8W-39Powertrain/Drivetrain Systems
8W-40 thru
8W-49Body Electrical items and A/C
8W-50 thru
8W-59Exterior Lighting, Wipers and
Trailer Tow
8W-60 thru
8W-69Power Accessories
8W-70 Splice Information
8W-80 Connector Pin Outs
8W-91 Connector, Ground and Splice
Locations
8W - 01 - 6 8W-01 WIRING DIAGRAM INFORMATIONDR
WIRING DIAGRAM INFORMATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Glove Box Lamp and Switch BK At Glove Box 35, 39
Governor Pressure Sensor BK Left Rear of Transmission N/S
Hands Free Module Right Instrument Panel 39
Headlamp Switch BK Left Side of Instrument Panel 32, 35, 38
Headlamp-Left BL At Headlamp 23, 28, 29
Headlamp-Right BL At Headlamp 1, 21, 26
Heated Seat Cushion - Driver BL Under Driver Seat N/S
Heated Seat Cushion - Passenger BL Under Passenger Seat N/S
Heated Seat Switch-Driver RD Center of Instrument Panel 33, 35, 36
Heated Seat Switch-Passenger BL Center of Instrument Panel 33, 35, 36
Horn Switch WT In Steering Wheel N/S
Horn-High Note BK Left Front Fender 23, 28, 29
Horn-Low Note BK Left Front Fender 23, 29
Idle Air Control Motor BK On Throttle Body 6
Ignition Coil GY Left Rear of Engine N/S
Ignition Switch BK Steering Column 31
Inlet Air Temperature/Pressure
SensorBK Right Side Engine 10
Input Speed Sensor BK At Transmission 15, 16
Instrument Cluster C1 GY Rear of Instrument Cluster 35
Instrument Cluster C2 GY Rear of Instrument Cluster 35
Instrument Cluster C3 WT Rear of Instrument Cluster 35
Intake Air Heater Relay Right Engine Compartment 2
Intake Air Temperature/Manifold
Absolute Pressure Sensor (Diesel)BK Left rear Engine N/S
Intake Air Temperature Sensor BK On Intake Manifold 5
Integrated Power Module C1 BK Left Front Fender 26, 28
Integrated Power Module C2 WT Left Front Fender 26, 28
Integrated Power Module C3 GR Left Front Fender 26, 28
Integrated Power Module C4 WT Left Front Fender 26, 28
Integrated Power Module C5 BK Left Front Fender 26, 28
Integrated Power Module C6 BK Left Front Fender 25, 26, 28
Integrated Power Module C7 GY Left Front Fender 26, 28
Integrated Power Module FCM BK In IPM N/S
Knock Sensor BK Left Rear of Engine 5, 7, 9
License Lamp-Left BK At Rear Bumper 50, 51
License Lamp-Right BK At Rear Bumper 50, 51
Lift Pump Motor BK Near T/O for WIF Sensor N/S
Line Pressure Sensor BK Right Rear of Transmission 15, 18
Lumbar Motor-Driver DK GY At Driver Seat N/S
Lumbar Motor-Passenger BK At Passenger Seat N/S
Manifold Absolute Pressure Sensor GY Left Front of Intake Manifold 6
Mode Door Actuator 1 BK Right Side of HVAC N/S
DR8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 5
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Speed Control Switch-Right (ETC) WT At Steering Wheel N/S
Starter Solenoid Left Engine 23
Tail/Stop/Turn Signal Lamp-Left BK At Lamp 50, 51
Tail/Stop/Turn Signal Lamp-Right BK At Lamp 50, 51
Throttle Position Sensor NAT Throttle Body 6
Trailer Tow Connector BK At Trailer Hitch 51
Trailer Tow Connector-Add On BK At Trailer Hitch 51, 53
Transfer Case Control Module C1 BK Left Side of Instrument Panel 35, 38
Transfer Case Control Module C2 GY Left Side of Instrument Panel 35, 38
Transfer Case Control Module C3 BK Left Side of Instrument Panel 35, 38
Transfer Case Mode Sensor BK Left Front Side of Transfer Case 13, 14, 16, 20
Transfer Case Position Sensor BK Front Middle of Transfer Case 20
Transfer Case Selector Switch BK Center of Instrument Panel 11, 12, 33, 35, 36
Transfer Case Shift Motor BK Left Rear of Transmission 13, 14, 20
Transmission Range Sensor BK Left side of Transmission 11, 14
Transmission Solenoid Assembly BK Left Side of Transmission 14, 11
Transmission Solenoid/TRS
Assembly (3.7L/4.7L)BK Left Side of Transmission 15, 16
Underhood Lamp BK Underside of Hood 29
Vacuum Pump (Diesel) Right Rear Engine Compartment 21
Vistronic Fan Drive Front Engine Compartment 28
Washer Fluid Level Switch BK At Reservoir 21, 23, 26, 28
Washer Pump Motor-Front BK At Washer Fluid Reservoir 21, 23, 26, 28
Water In Fuel Sensor (Diesel) BK Right Side Engine 10
Wheel Speed Sensor-Left Front BK Left Rear Lower Side of Engine
Compartment22, 29
Wheel Speed Sensor-Rear BK Right Rear of Body 51
Wheel Speed Sensor-Right Front GY Right Rear Lower Side of Engine
Compartment21
Wiper Motor-Front BK Left Side of Cowl 22, 25
8W - 91 - 8 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

SPLICE
NUMBERLOCATION FIG.
S176 Left Side Engine Near T/O for Fuel Control Actuator N/S
S187 Rear of Engine 7
S191 Near Integrated Power Module 23
S203 Right Side Engine Compartment 23
S204 Left Side of Instrument Panel 35
S205 Left Side of Instrument Panel 35
S206 At Steering Column N/S
S207 At Steering Column N/S
S209 Center of Instrument Panel 35
S210 Center of Instrument Panel 35, 38
S212 Left Side of Instrument Panel 31, 38
S214 Left Side of Instrument Panel 31, 38
S216 Center of Instrument Panel 35, 36
S217 Left Side of Instrument Panel N/S
S218 Left Side of Instrument Panel N/S
S219 Center of Instrument Panel N/S
S220 Center of Instrument Panel N/S
S221 Center of Instrument Panel 35, 39
S222 Center of Instrument Panel 35
S224 Right Side of HVAC N/S
S225 Center of Instrument Panel 35
S226 Right Side of HVAC N/S
S228 At Steering Column N/S
S230 Right Instrument Panel 35
S231 Left Instrument Panel 38
S232 Right Engine Compartment 23
S240 Steering Column 31, 38
S241 Center Instrument Panel 35, 36
S243 Right Engine Compartment 23
S245 Left Instrument Panel 35
S300 Left Kick Panel 40, 44, 46
S301 Center of Headliner N/S
S302 Center of Headliner N/S
S303 Middle of Roof 48
S304 Center of Headliner N/S
S305 Middle of Roof 48
S306 Left Side of Frame N/S
S307 Center of Headliner N/S
S308 Left Rear Chassis 50, 51
S309 Center Rear of Chassis 51
S311 Left Front of Body 44, 46
DR8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 11
CONNECTOR/GROUND/SPLICE LOCATION (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)

(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)