1998 DODGE RAM 1500 ECU

INSTALLATION
(1) Position the wiper high/low relay to the proper
receptacle in the Integrated Power Module (IPM)
(Fig. 24).
(2) Align the wiper high/low relay terminals with
the terminal cavities in the IPM receptacle.
(3) Push firmly and evenly on the top of the wiper
high/low relay until the terminals are fully seated in
the terminal cavities in the IPM receptacle.
(4) Reinstall the cover onto the IPM.
(5) Reconnect the battery negative cable.
WIPER MODULE
DESCRIPTION
The wiper motor bracket is secured with two
screws below the wiper motor through two rubber
insulators to the bottom of the cowl plenum panel
beneath the cowl plenum cover/grille panel (Fig. 25).
Two screws secure the top of the wiper module
bracket to the cowl plenum panel through rubber
insulators located on the outboard end of each pivot
bracket. The ends of the wiper pivot shafts that pro-
trude through dedicated openings in the cowl plenum
cover/grille panel to drive the wiper arms and bladesare the only visible components of the wiper module.
The wiper module consists of the following major
components:
²Bracket- The wiper module bracket consists of
a long tubular steel main member that has a die cast
pivot bracket formation near each end where the two
wiper pivots are secured. A stamped steel clamp
secures the center of the tubular member to the die
cast bracket integral to the wiper motor with two
screws.
²Crank Arm- The wiper motor crank arm is a
stamped steel unit with a slotted hole on the driven
end that is secured to the wiper motor output shaft
with a nut, and has a ball stud secured to the drive
end.
²Linkage- Two stamped steel drive links con-
nect the wiper motor crank arm to the wiper pivot
lever arms. The left side drive link has a plastic sock-
et-type bushing on each end. The right side drive
link has a plastic socket-type bushing on one end,
and a plastic sleeve-type bushing on the other end.
The socket-type bushing on one end of each drive
link is snap-fit over the ball stud on the lever arm of
its respective pivot. The right side drive link sleeve-
type bushing end is then fit over the motor crank
arm ball stud, and the other socket-type bushing of
the left side drive link is snap-fit over the exposed
end of the wiper motor crank arm ball stud.
²Motor- The wiper motor features an integral
die cast bracket to which the wiper module bracket is
secured with a stamped steel clamp and two screws
near the top and which has two rubber insulated
mounting ears at the bottom. This die casting also
serves as the wiper motor transmission housing from
which the wiper motor output shaft exits. A nut
secures the wiper motor crank arm to the motor out-
put shaft. The two-speed permanent magnet wiper
motor features an integral transmission, an internal
park switch, and an internal automatic resetting cir-
cuit breaker.
²Pivots- The two front wiper pivots are secured
within the die cast pivot brackets on the outboard
ends of the wiper module main member. The lever
arms that extend from the center of the pivot shafts
each have a ball stud on their end. The upper end of
each pivot shaft where the wiper arms will be fas-
tened each has a serrated driver with a keyway. The
lower ends of the pivot shafts are installed through
lubricated bushings in the pivot brackets and are
secured with snap rings.
The wiper module cannot be adjusted or repaired.
If any component of the module is faulty or damaged,
the entire wiper module unit must be replaced.
Fig. 25 Wiper Module
1 - PIVOT BRACKET (2)
2 - TUBE
3 - CLAMP
4 - PIVOT SHAFT (2)
5 - INSULATOR (4)
6 - LINKAGE BUSHING (4)
7 - DRIVE LINK (2)
8 - PIVOT CRANK ARM (2)
9 - PIGTAIL WIRE CONNECTOR
10 - MOTOR CRANK ARM
11 - WIPER MOTOR
8R - 22 WIPERS/WASHERSDR
WIPER HIGH/LOW RELAY (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)

The wiper on/off relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The wiper on/off relay is an electromechanical
switch that uses a low current input from the Front
Control Module (FCM) to control a high current out-
put to the wiper motor. The movable common feed
contact point is held against the fixed normally
closed contact point by spring pressure. When the
relay coil is energized, an electromagnetic field is
produced by the coil windings. This electromagnetic
field draws the movable relay contact point away
from the fixed normally closed contact point, and
holds it against the fixed normally open contact
point. When the relay coil is de-energized, spring
pressure returns the movable contact point back
against the fixed normally closed contact point. A
resistor is connected in parallel with the relay coil in
the relay, and helps to dissipate voltage spikes and
electromagnetic interference that can be generated as
the electromagnetic field of the relay coil collapses.
The wiper on/off relay terminals are connected to
the vehicle electrical system through a connector
receptacle in the Integrated Power Module (IPM).
The inputs and outputs of the wiper on/off relay
include:
²Common Feed Terminal- The common feed
terminal (30) is connected to the common feed termi-
nal of the wiper high/low relay at all times through
the wiper on/off relay output circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the Front
Control Module (FCM) through a wiper on/off relay
control circuit. The FCM controls wiper motor opera-
tion by controlling a ground path through this cir-
cuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery current at all times from
a fuse in the IPM through a fused ignition switch
output (run-acc) circuit.
²Normally Open Terminal- The normally open
terminal (87) receives battery current at all times
from a fuse in the IPM through a fused ignition
switch output (run-acc) circuit, and provides battery
current to the wiper on/off relay output circuit when-
ever the relay is energized.²Normally Closed Terminal- The normally
closed terminal (87A) is connected to ground at all
times through a take out of the left headlamp and
dash wire harness with an eyelet terminal connector
that is secured by a screw to the front end sheet
metal, and is connected to the wiper on/off relay out-
put circuit whenever the relay is de-energized.
The wiper on/off relay may be diagnosed using con-
ventional diagnostic tools and methods. However,
conventional diagnostic methods may not prove con-
clusive in the diagnosis of the instrument cluster, the
Front Control Module (FCM), or the electronic mes-
sage inputs to or outputs from the instrument cluster
and the FCM that control the operation of the wiper
on/off relay. The most reliable, efficient, and accurate
means to diagnose the wiper on/off relay, the instru-
ment cluster, the FCM, or the electronic message
inputs and outputs related to the wiper on/off relay
operation requires the use of a DRBIIItscan tool.
Refer to the appropriate diagnostic information.
DIAGNOSIS AND TESTING - WIPER ON/OFF
RELAY
The wiper on/off relay (Fig. 28) is located in the
Integrated Power Module (IPM) in the engine com-
partment near the battery. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and location
views for the various wire harness connectors, splices
and grounds.
Fig. 28 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
DRWIPERS/WASHERS 8R - 25
WIPER ON/OFF RELAY (Continued)

WIRING
TABLE OF CONTENTS
page page
WIRING DIAGRAM INFORMATION....... 8W-01-1
COMPONENT INDEX.................. 8W-02-1
POWER DISTRIBUTION............... 8W-10-1
GROUND DISTRIBUTION.............. 8W-15-1
BUS COMMUNICATIONS.............. 8W-18-1
CHARGING SYSTEM.................. 8W-20-1
STARTING SYSTEM.................. 8W-21-1
FUEL/IGNITION SYSTEM.............. 8W-30-1
TRANSMISSION CONTROL SYSTEM..... 8W-31-1
VEHICLE SPEED CONTROL............ 8W-33-1
REAR WHEEL ANTILOCK BRAKES....... 8W-34-1
ALL WHEEL ANTILOCK BRAKES........ 8W-35-1
VEHICLE THEFT SECURITY SYSTEM..... 8W-39-1
INSTRUMENT CLUSTER............... 8W-40-1
HORN/CIGAR LIGHTER/POWER OUTLET . . 8W-41-1
AIR CONDITIONING.................. 8W-42-1
AIRBAG SYSTEM.................... 8W-43-1
INTERIOR LIGHTING.................. 8W-44-1AUDIO SYSTEM..................... 8W-47-1
REAR WINDOW DEFOGGER............ 8W-48-1
OVERHEAD CONSOLE................. 8W-49-1
FRONT LIGHTING.................... 8W-50-1
REAR LIGHTING..................... 8W-51-1
TURN SIGNALS...................... 8W-52-1
WIPERS............................ 8W-53-1
TRAILER TOW....................... 8W-54-1
NAVIGATION/TELECOMMUNICATION..... 8W-55-1
POWER WINDOWS................... 8W-60-1
POWER DOOR LOCKS................ 8W-61-1
POWER MIRRORS................... 8W-62-1
POWER SEATS...................... 8W-63-1
SPLICE INFORMATION................ 8W-70-1
CONNECTOR PIN-OUTS............... 8W-80-1
CONNECTOR/GROUND/SPLICE
LOCATION........................ 8W-91-1
POWER DISTRIBUTION............... 8W-97-1 DRWIRING 8W - 1

8W-39 VEHICLE THEFT SECURITY SYSTEM
Component Page
Cylinder Lock Switch-Driver........... 8W-39-5
Data Link Connector................. 8W-39-3
Door Lock Motor/Ajar Switch-Driver..... 8W-39-5
Door Lock Motor/Ajar Switch-Left Rear . . . 8W-39-5
Door Lock Motor/Ajar Switch-Passenger . . 8W-39-4
Door Lock Motor/Ajar Switch-Right Rear . . 8W-39-4
Front Control Module................. 8W-39-3
Fuse 15............................ 8W-39-3
Fuse 23............................ 8W-39-2
Fuse 45............................ 8W-39-3
Fuse 50............................ 8W-39-2Component Page
G104.............................. 8W-39-3
G105.............................. 8W-39-3
G201.............................. 8W-39-2
G301............................ 8W-39-4, 5
Headlamp-Left...................... 8W-39-3
Headlamp-Right..................... 8W-39-3
Horn Relay......................... 8W-39-3
Instrument Cluster............... 8W-39-2, 4, 5
Integrated Power Module............ 8W-39-2, 3
Park Lamp Relay.................... 8W-39-3
Sentry Key Immobilizer Module......... 8W-39-2
DR8W-39 VEHICLE THEFT SECURITY SYSTEM 8W - 39 - 1

C302 - BLACK (PASSENGER DOOR SIDE)
CAV CIRCUIT
1 F21 20PK/DG
2-
3-
4 G778 18VT/LB
5-
6 G160 20VT/LG
7 Q16 14OR/TN
8 Q26 14OR/GY
9-
10 P392 18LG/DB
11 Z216 20BK/DB
12 -
13 C16 18DB/GY
14 -
15 -
16 -
C304 - (BODY SIDE)
CAV CIRCUIT
1 G75 20VT
2 P195 18LG/YL (SLT)
3 P72 18TN/GY (SLT)
4 X153 18DG/YL
5 X155 18DG/LB
6 P74 18TN/OR (SLT)
7 F30 12PK/YL (SLT)
8 Q15 12OR/LB (SLT)
9 A930 18RD (SLT)
10 Z75 20BK/VT
C304 - (DRIVER DOOR SIDE)
CAV CIRCUIT
1 G75 20VT
2 P195 18LG/YL (POWER WINDOW/
LOCKS)
3 P72 20TN/GY (POWER WINDOW/
LOCKS EXCEPT SECURITY)
3 P72 18 TN/GY (SECURITY)
4 X153 18DG/YL
5 X155 18DG/LB
6 P74 18TN/OR (POWER WINDOW/
LOCKS)
7 F30 14PK/YL (POWER WINDOW/
LOCKS)
8 Q15 14OR/LB (POWER WINDOW/
LOCKS)
9 A930 18RD (POWER WINDOW/LOCKS)
10 Z75 20BK/VT (EXCEPT SECURITY)
10 Z463 20BK/LB (SECURITY)
8W - 80 - 34 8W-80 CONNECTOR PIN-OUTSDR

8W-97 POWER DISTRIBUTION
TABLE OF CONTENTS
page page
POWER DISTRIBUTION
DESCRIPTION..........................1
OPERATION............................1
SPECIAL TOOLS
POWER DISTRIBUTION SYSTEMS.........2
CIGAR LIGHTER OUTLET
DESCRIPTION..........................2
OPERATION............................2
DIAGNOSIS AND TESTING - CIGAR LIGHTER
OUTLET.............................2
INTEGRATED POWER MODULE
DESCRIPTION..........................3
OPERATION............................3
REMOVAL.............................3
INSTALLATION..........................4
FRONT CONTROL MODULE
DESCRIPTION..........................5OPERATION............................5
DIAGNOSIS AND TESTING - FRONT
CONTROL MODULE....................5
REMOVAL.............................6
INSTALLATION..........................6
IOD FUSE
DESCRIPTION..........................6
OPERATION............................6
REMOVAL.............................7
INSTALLATION..........................7
POWER OUTLET
DESCRIPTION..........................7
OPERATION............................7
DIAGNOSIS AND TESTING - POWER
OUTLET.............................7
REMOVAL.............................8
INSTALLATION..........................8
POWER DISTRIBUTION
DESCRIPTION
This group covers the various standard and
optional power distribution components used on this
model. The power distribution system for this vehicle
consists of the following components:
²Integrated Power Module (IPM)
²Front Control Module (FCM)
²Power Distribution Center (PDC)
²Power Outlets
²Cigar Lighter Outlets
²Relays
Refer to Wiring Diagrams for complete circuit sche-
matics.
The power distribution system also incorporates
various types of circuit control and protection fea-
tures, including:
²Automatic resetting circuit breakers
²Blade-type fuses
²Cartridge fuses
²Relays
Following are general descriptions of the major
components in the power distribution system. See the
owner's manual in the vehicle glove box for more
information on the features and use of all of the
power distribution system components.
OPERATION
The power distribution system for this vehicle is
designed to provide safe, reliable, and centralized dis-
tribution points for the electrical current required to
operate all of the many standard and optional facto-
ry-installed electrical and electronic powertrain,
chassis, safety, security, comfort and convenience sys-
tems. At the same time, the power distribution sys-
tem was designed to provide ready access to these
electrical distribution points for the vehicle techni-
cian to use when conducting diagnosis and repair of
faulty circuits. The power distribution system can
also prove useful for the sourcing of additional elec-
trical circuits that may be required to provide the
electrical current needed to operate many accessories
that the vehicle owner may choose to have installed
in the aftermarket.
DR8W-97 POWER DISTRIBUTION 8W - 97 - 1

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)