1998 DODGE RAM 1500 Electronic

C218 - NATURAL (HEADLAMP AND DASH SIDE)
CAV CIRCUIT
1-
2 A405 18RD/DB
3 C16 16DB/GY (EXCEPT 3.7L BASE)
4 A930 18RD (EXCEPT 3.7L BASE)
5-
6-
7-
8-
9 A210 12OR/RD (EXCEPT 3.7L BASE)
10 -
11 -
12 C15 16DB/WT (EXCEPT 3.7L BASE)
C219 - (HEADLAMP AND DASH SIDE)
CAV CIRCUIT
1 C110 20DB/LB (TRAILER TOW)
2 D15 18WT/DG (NGC)
3 L50 18WT/TN
4 F1 16PK/WT (NGC)
5 D21 20WT/BR
6 A103 18GY/RD
7 T751 16YL
8 D20 20WT/LG
9 E11 20OR/DB (ELECTRONIC TRANSFER
CASE)
10 A970 10RD
11 A991 10RD (TRAILER TOW)
12 -
13 -
14 -
15 -
16 V38 20VT/OR (5.7L)
17 V37 20VT
18 T6 20DG (GAS/DIESEL A/T)
19 L70 18WT/GY
20 F21 20PK/DG
21 V32 20VT/YL
22 -
23 A921 16RD
24 B25 20DG/WT
25 F202 20PK/GY (5.7L)
25 V30 20VT/WT (GAS EXCEPT 5.7L/DIE-
SEL A/T)
26 A114 18GY/RD
27 L1 18WT/LG
28 -
29 -
30 V937 20VT/BR (5.7L)
30 K900 20DB/DG (EXCEPT 5.7L)
31 A944 20RD
32 F504 20GY/PK
33 A941 18RD
34 -
DR8W-80 CONNECTOR PIN-OUTS 8W - 80 - 27

INSTRUMENT CLUSTER C2 - GRAY 16 WAY
CAV CIRCUIT FUNCTION
1 G194 20VT/LG WASH/BEAM SELECT SWITCH SIGNAL
2 G160 20VT/LG (SLT)8PASSENGER DOOR LOCK SWITCH MUX
3 G161 20VT/DG (SLT) DRIVER DOOR LOCK SWITCH MUX
4 E2 20OR/BR PANEL LAMPS DIMMER SIGNAL
5 L116 20WT/LG HEADLAMP SWITCH SIGNAL
6- -
7 G163 20VT/LB (SLT) DRIVER CYLINDER LOCK SWITCH MUX
8 L12 20WT/OR TURN LAMPS SWITCH SIGNAL
9- -
10 W52 20BR/YL INTERMITTENT WIPER SWITCH SIGNAL
11 T117 20DG/YL TRANS RANGE SENSOR ELECTRONIC CLUSTER 5
VOLT SUPPLY
12 X20 20GY/WT (SLT PREMIUM RADIO) RADIO CONTROL MUX
13 - -
14 - -
15 - -
16 - -
INSTRUMENT CLUSTER C3 - GRAY 26 WAY
CAV CIRCUIT FUNCTION
1 G75 20VT DRIVER DOOR AJAR SWITCH SENSE
2 G77 20VT/GY LEFT REAR DOOR AJAR SWITCH SENSE
3 G76 20VT/YL RIGHT REAR DOOR AJAR SWITCH SENSE
4 G74 20VT/WT PASSENGER DOOR AJAR SWITCH SENSE
5- -
6- -
7 K77 18BR/WT TRANSFER CASE POSITION SENSOR INPUT
8 L900 20WT/YL WIPER/TURN/BEAM SELECT SWITCH RETURN
9 L115 20WT/YL HEADLAMP SWITCH RETURN
10 T917 20YL/TN TRANS RANGE SENSOR ELECTRONIC CLUSTER MUX
11 - -
12 - -
13 Z18 20BK/LB GROUND
14 X3 20DG/VT HORN SWITCH SENSE
15 L50 18WT/TN BRAKE LAMP SWITCH OUTPUT
16 G15 20VT/TN KEY IN IGNITION SWITCH SENSE
17 - -
18 - -
19 D25 20WT/VT PCI BUS
20 G10 20VT/LG SEAT BELT SWITCH SENSE
21 - -
22 B25 20DG/WT PARK BRAKE SWITCH SENSE
23 F983 20PK/YL FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
24 F1 16PK/WT FUSED IGNITION SWITCH OUTPUT (OFF-RUN-START)
25 F21 20PK/DG FUSED IGNITION SWITCH OUTPUT (RUN-START)
26 A114 18GY/RD FUSED B(+)
8W - 80 - 72 8W-80 CONNECTOR PIN-OUTSDR

INTEGRATED POWER MODULE C2 - WHITE 15 WAY
CAV CIRCUIT FUNCTION
1 A991 10RD FUSED B(+)
2 A34 16RD/WT (ELECTRONIC TRANS-
FERCASE))FUSED B(+)
3 A405 18RD/DB FUSED B(+)
4- -
5 A210 12OR/RD FUSED B(+)
6 A970 10RD FUSED B(+)
7 A100 14RD/VT FUSED B(+)
8 A111 14DG/RD FUSED B(+)
9 A205 18RD/OR FUSED B(+)
10 A921 16RD FUSED B(+)
11 - -
12 F984 18PK/YL FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
13 A116 18YL/RD FUSED B(+)
14 A951 16RD FUSED B(+)
15 - -
INTEGRATED POWER MODULE C3 - 16 WAY
CAV CIRCUIT FUNCTION
1 W10 20BR WASHER PUMP MOTOR CONTROL
2 L62 18WT/YL RIGHT REAR TURN LAMP DRIVER
3 Z117 18BK/WT GROUND
4 G31 20VT/LG (DIESEL) AAT SIGNAL
5 Z118 18BK/YL GROUND
6 L1 18WT/LG BACKUP LAMP FEED
7- -
8- -
9- -
10 D25 20VT/PK PCI BUS
11 - -
12 L61 18WT/LG LEFT FRONT TURN LAMP DRIVER
13 L53 18DG/WT LEFT STOP LAMP FEED
14 L63 18WT/DG LEFT REAR TURN LAMP DRIVER
15 L60 18WT/TN RIGHT FRONT TURN LAMP DRIVER
16 G180 20VT/YL (DIESEL) SENSOR GROUND
8W - 80 - 74 8W-80 CONNECTOR PIN-OUTSDR

TRANSMISSION RANGE SENSOR-6WAY
CAV CIRCUIT FUNCTION
1 L10 18WT/GY FUSED IGNITION SWITCH OUTPUT (RUN)
2 T117 20DG/YL TRANS RANGE SENSOR ELECTRONIC CLUSTER 5
VOLT SUPPLY
3- -
4 L1 18WT/LG BACKUP LAMP FEED
5 T917 20YL/TN TRANS RANGE SENSOR ELECTRONIC CLUSTER MUX
6 T41 20YL/DB PARK NEUTRAL POSITION SWITCH SENSE (T41)
6 T41 18YL/DB PARK NEUTRAL POSITION SWITCH SENSE (T41)
TRANSMISSION SOLENOID ASSEMBLY (48RE)-8WAY
CAV CIRCUIT FUNCTION
1 T16 18YL/OR TRANSMISSION CONTROL RELAY OUTPUT
2 F856 18YL/PK 5 VOLT SUPPLY
3 K900 20DB/DG SENSOR GROUND
3 K900 18DB/DG SENSOR GROUND
4 T38 18YL/BR GOVERNOR PRESSURE SENSOR SIGNAL
5 T118 18DG GOVERNOR PRESSURE SOLENOID CONTROL
6 T9 18DG/TN 3-4 SHIFT SOLENOID
7 T75 18YL/LB TORQUE CONVERTER CLUTCH SOLENOID CONTROL
8 T54 18DG/OR TRANSMISSION TEMPERATURE SENSOR SIGNAL
TRANSMISSION SOLENOID/TRS ASSEMBLY (NGC) - 23 WAY
CAV CIRCUIT FUNCTION
1 L10 18WT/GY FUSED IGNITION SWITCH OUTPUT (RUN)
2 T20 18DG/WT L/R SOLENOID CONTROL
3- -
4 T41 20YL/DB TRS T41 SENSE
5 T42 18DG/YL TRS T42 SENSE
6 L1 18WT/LG BACKUP LAMP FEED
7 T60 18YL/GY OVERDRIVE SOLENOID CONTROL
8 T3 18DG/DB TRS T3 SENSE
9 T1 18DG/LB TRS T1 SENSE
10 T16 18YL/OR TRANSMISSION CONTROL RELAY OUTPUT
11 T48 18BR/YL 4C PRESSURE SWITCH SENSE
12 T140 18YL/GY PRESSURE CONTROL SOLENIOD CONTROL
13 T4 18DG/LB TRS T2 SENSE
14 T50 18YL/TN LOW/REVERSE PRESSURE SWITCH SENSE
15 T147 18DG/YL 2C PRESSURE SWITCH SENSE
16 T9 18DG/TN OVERDRIVE PRESSURE SWITCH SENSE
17 T59 18YL/LB UNDERDRIVE SOLENOID CONTROL
18 T29 18YL/WT UNDERDRIVE PRESSURE SWITCH SENSE
19 T259 18YL/DG 4C SOLENOID CONTROL
20 T219 18YL/LG 2C SOLENOID CONTROL
21 T118 18DG MS SOLENOID CONTROL
22 K900 18DB/DG SENSOR GROUND
23 T54 18DG/OR TRANSMISSION TEMPERATURE SENSOR SIGNAL
8W - 80 - 102 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

INTEGRATED POWER MODULE
DESCRIPTION
The Integrated Power Module (IPM) (Fig. 1) is a
combination of the Power Distribution Center (PDC)
and the Front Control Module (FCM). The IPM is
located in the engine compartment, next to the bat-
tery on this model. The power distribution center
mates directly with the Front Control Module (FCM)
to form the Integrated Power Module Fuse and Relay
Center. The power distribution center (PDC) is a
printed circuit board based module that contains
fuses and relays, while the front control module con-
tains the electronics controlling the integrated power
module and other functions. This integrated power
module connects directly to the battery positive via a
stud located on top of the unit. The ground connec-
tion is via electrical connectors. The integrated power
module provides the primary means of voltage distri-
bution and protection for the entire vehicle.
The molded plastic integrated power module hous-
ing includes a base and cover. The integrated power
module cover is easily opened or removed for service
access by unscrewing the cover retaining nut and has
a fuse and relay layout map integral to the inside
surface of the cover. This integrated power module
housing base and cover are secured in place via bolts
to the left front fender support assembly.
Replaceable components of the integrated power
module assembly are broken down into the followingcomponents: the Power Distribution Center (PDC),
the integrated power module cover, the Front Control
Module (FCM) and the Integrated Power Module
Assembly which includes the power distribution cen-
ter, the cover and FCM.Refer to the Front Con-
trol Module in the Electronic Control Module
sectionof this service manual for information on the
front control module.
OPERATION
All of the current from the battery and the gener-
ator output enters the integrated power module via a
stud on the top of the module. The integrated power
module cover is removed to access the fuses or relays.
Internal connections of all of the power distribution
center circuits is accomplished by a combination of
bus bars and a printed circuit board. Refer to the
Wiring section of the service manual for complete
integrated power module circuit schematics.
REMOVAL
(1) Disconnect the negative and positive battery
cables.
(2) Unsnap cover and remove the B+ terminal nut
from the integrated power module B+ terminal.
Remove the B+ cable from the integrated power mod-
ule.
(3) Disconnect the gray connector from the inte-
grated power module.
Fig. 1 DR INTEGRATED POWER MODULE
1 - POWER DISTRIBUTION CENTER HOUSING
2 - FRONT CONTROL MODULE ELECTRICAL CONNECTOR
Fig. 2 DR INTEGRATED POWER MODULE
1 - COVER RETAINING BOLT
2 - INTEGRATED POWER MODULE RETAINING BOLT
3 - RETAINING SCREW
4 - INTEGRATED POWER MODULE COVER
DR8W-97 POWER DISTRIBUTION 8W - 97 - 3

(3) Connect the electrical connectors by pushing
straight on and rotating the connector arm inboard,
until the connector is firmly locked in place on the
module assembly.
(4) Grasp the integrated power module with two
hands and install the assembly on the battery tray
(Fig. 5).
(5) Install the integrated power module retaining
bolt and screw.
(6) Connect the gray connector on the integrated
power module housing.
(7) Install the B+ terminal cable and nut on the
integrated power module B+ terminal. Snap the
cover in place.
(8) Connect the negative and positive battery
cables.
FRONT CONTROL MODULE
DESCRIPTION
The Front Control Module (FCM) is a micro con-
troller based module located in the left front corner
of the engine compartment. On this model the inte-
grated power module must be positioned aside in
order to access the front control module. The front
control module mates to the power distribution cen-
ter to form the Integrated Power Module (IPM). Theintegrated power module connects directly to the bat-
tery and provides the primary means of circuit pro-
tection and power distribution for all vehicle
electrical systems. The front control module controls
power to some of these vehicle systems electrical and
electromechanical loads based on inputs received
from hard wired switch inputs and data received on
the PCI bus circuit (J1850).
For information on theIntegrated Power Mod-
ule Refer to the Power Distribution Sectionof
the service manual.
OPERATION
As messages are sent over the PCI bus circuit, the
front control module reads these messages and con-
trols power to some of the vehicles electrical systems
by completing the circuit to ground (low side driver)
or completing the circuit to 12 volt power (high side
driver). The following functions areControlledby
the Front Control Module:
²Headlamp Power with Voltage Regulation
²Windshield Wiper ªON/OFFº Relay Actuation
²Windshield Wiper ªHI/LOº Relay Actuation
²Windshield Washer Pump Motor
²Fog Lamp Relay Actuation
²Park Lamp Relay Actuation
²Horn Relay Actuation
The following inputs areReceived/Monitoredby
the Front Control Module:
²B+ Connection Detection
²Power Ground
²Ambient Temperature Sensing
²Ignition Switch Run
²Washer Fluid Level Switch
²Windshield Wiper Park Switch
²PCI Bus Circuit
DIAGNOSIS AND TESTING - FRONT CONTROL
MODULE
The front control module is a printed circuit board
based module with a on-board micro-processor. The
front control module interfaces with other electronic
modules in the vehicle via the Programmable Com-
munications Interface (PCI) data bus (J1850). In
order to obtain conclusive testing the Programmable
Communications Interface (PCI) data bus network
and all of the electronic modules that provide inputs
to, or receive outputs from the front control module
must be checked. All PCI (J1850) communication
faults must be resolved prior to further diagnosing
any front control module related issues.
The front control module was designed to be diag-
nosed with an appropriate diagnostic scan tool, such
as the DRB IIIt. The most reliable, efficient, and
accurate means to diagnose the front control module
Fig. 5 INTEGRATED POWER MODULE MOUNTING
TABS
1 - INTEGRATED POWER MODULE MOUNTING HOLES
2 - BATTERY TRAY ASSEMBLY
3 - FRONT CONTROL MODULE
DR8W-97 POWER DISTRIBUTION 8W - 97 - 5
INTEGRATED POWER MODULE (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)