2002 DODGE RAM engine

Fig. 12 IGNITION COIL (GAS ENGINE)
8W - 91 - 20 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONBR/BE
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

Fig. 14 ACCELERATOR PEDAL POSITION SENSOR
Fig. 15 ENGINE CONTROL MODULE
8W - 91 - 22 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONBR/BE
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

Fig. 17 LEFT SIDE TRANSMISSION 8.0 LITER ENGINE
8W - 91 - 24 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONBR/BE
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

Fig. 18 LEFT SIDE ENGINE COMPARTMENT
BR/BE8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 25
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

Fig. 19 LEFT SIDE ENGINE COMPARTMENT
8W - 91 - 26 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONBR/BE
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

tor between many of the engine compartment, instru-
ment panel, and body wire harnesses. The JB houses
up to nineteen blade-type fuses (two standard-type
and seventeen mini-type), up to two blade-type auto-
matic resetting circuit breakers, the electronic combi-
nation turn signal and hazard warning flasher, and
one International Standards Organization (ISO)
micro-relay.
The molded plastic JB housing has integral mount-
ing brackets that are secured with two screws to the
left instrument panel end bracket. The left end of the
instrument panel cover has a snap-fit fuse access
panel that can be removed for service of the JB. A
fuse puller and spare fuse holders are located on the
back of the fuse access cover, as well as an adhesive-
backed fuse layout map to ensure proper fuse identi-
fication.
The JB unit cannot be repaired and is only ser-
viced as an assembly. If any internal circuit or the JB
housing is faulty or damaged, the entire JB unit
must be replaced.
OPERATION
All of the circuits entering and leaving the JB do
so through up to nine wire harness connectors, which
are connected to the JB through integral connector
receptacles molded into the JB housing. Internal con-
nection of all of the JB circuits is accomplished by an
intricate combination of hard wiring and bus bars.
Refer toWiring Diagramsfor the location of com-
plete JB circuit diagrams.
DIAGNOSIS AND TESTING - JUNCTION BLOCK
The junction block does not incorporate any self
diagnostic capability. Most of the electrical circuits
incorporated into the vehicle must pass through the
junction block at one point or another. The most effi-
cient means of diagnosing a suspected junction block
problem involves a simple continuity tester or ohm
meter. Using the Wiring Diagrams as a guide trace
the problem circuit to the proper junction block cav-
ity and test all circuits in the effected circuit for
proper continuity. A open or high resistance circuit is
a sign of a problem. Some other possible junction
block problems to look for are:
²Loose fuse receptacle terminals.
²Loose relay / circuit breaker receptacle termi-
nals.
²Bent or distorted electrical circuit pins.
²Incorrect size fuse installed in junction block
fuse cavity.
²Dark areas identifying a source of excess heat.
²Defective fuse, relay or circuit breaker installed
in junction block cavity.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the fuse access bezel from the instru-
ment panel.
(3) Remove the steering column cover (Refer to 23
- BODY/INSTRUMENT PANEL/STEERING COL-
UMN OPENING COVER - REMOVAL).
(4) Remove the hood release handle retaining
screws and position the handle assembly out of the
way.
(5) Remove the lower knee blocker from the instru-
ment panel.
(6) Pull drivers side carpet down, out of the way.
(7) Remove the parking brake switch connector,
release linkage and retaining fasteners and position
the assembly out the drivers door opening.
(8) Remove the electrical ground connections,
located behind park brake mounting location.
(9) Remove the two junction block retaining
screws. To access the upper retaining screw a 15 inch
long #2 Phillips screwdriver will be required. Access
the upper screw through hole in dash support brace.
(10) Reach through the outboard side of the instru-
ment panel steering column opening to access and
disconnect all of the wire harness connectors from
the Junction Block (JB) connector receptacles (Fig.
6).
Fig. 6 Junction Block Remove/Install
1 - I.P. End Bracket
2 - Junction Block
3 - Screws
BR/BE8W-97 POWER DISTRIBUTION 8W - 97 - 7
JUNCTION BLOCK (Continued)

(11) Remove the junction block from under the
instrument panel.
INSTALLATION
NOTE: If the Junction Block (JB) is being replaced
with a new unit, be certain to transfer each of the
fuses, circuit breakers and relays from the faulty JB
to the proper cavities of the replacement JB. Refer
to Junction Block in the index of this service man-
ual for the location of complete circuit diagrams
and cavity assignments for the JB.
(1) Position the junction block under the instru-
ment panel.
(2) Connect all of the wire harness connectors on
the Junction Block (JB) connector receptacles.
(3) Install the two junction block retaining screws.
(4) Install the electrical ground connections,
located behind park brake mounting location.
(5) Install the parking brake switch connector,
release linkage and retaining fasteners.
(6) Reposition drivers side carpet.
(7) Install the lower knee blocker on the instru-
ment panel.
(8) Install the hood release handle retaining
screws.
(9) Install the steering column cover.
(10) Install the fuse access bezel on the instrument
panel.
(11) Connect the battery negative cable.
POWER DISTRIBUTION
CENTER
DESCRIPTION
All of the electrical current distributed throughout
this vehicle is directed through the standard equip-
ment Power Distribution Center (PDC) (Fig. 7). The
molded plastic PDC housing is located in the left
front corner of the engine compartment, just behind
the battery. The PDC houses the generator cartridge
fuse and up to twelve maxi-type cartridge fuses,
which replace all in-line fusible links. The PDC also
houses up to thirteen blade-type fuses (two standard-
type and eleven mini-type), up to seventeen Interna-
tional Standards Organization (ISO) relays (five
standard-type and twelve micro-type), two joint con-
nectors (one eighteen-way and one twenty-eight-way),
a forty-three-way engine wire harness in-line connec-
tor and a fuse puller.
The PDC housing is secured in the engine compart-
ment on the outboard side with two screws to the left
front inner fender shield, and with a screw on the
inboard side to the left front inner wheel house. ThePDC housing has a molded plastic cover that
includes two integral latches, one on each side. The
PDC cover is easily opened and removed for service
access and has a convenient adhesive-backed fuse
and relay layout map affixed to the inside surface of
the cover to ensure proper component identification.
The PDC unit cannot be repaired and is only ser-
viced as a unit with the headlamp and dash wire
harness. If the internal circuits or the PDC housing
are faulty or damaged, the headlamp and dash wire
harness unit must be replaced.OPERATION
All of the current from the battery and the gener-
ator output enters the PDC through two cables with
eyelets that are secured with nuts to the two B(+)
terminal studs located just inside the inboard end of
the PDC housing. The PDC cover is unlatched and
removed to access the battery and generator output
connection B(+) terminal studs, the fuses, the relays,
the joint connectors and the engine wire harness in-
line connector. Internal connection of all of the PDC
circuits is accomplished by an intricate combination
of hard wiring and bus bars. Refer toWiring Dia-
gramsfor the location of complete PDC circuit dia-
grams.
REMOVAL
The Power Distribution Center (PDC) is serviced
as a unit with the headlamp and dash wire harness.
If any internal circuit of the PDC or the PDC hous-
Fig. 7 Power Distribution Center Location
1 - POWER DISTRIBUTION CENTER
8W - 97 - 8 8W-97 POWER DISTRIBUTIONBR/BE
JUNCTION BLOCK (Continued)

ing is faulty or damaged, the entire PDC and head-
lamp and dash wire harness unit must be replaced.
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect each of the headlamp and dash wire
harness connectors. Refer toConnector Locations
in Wiring for the location of more information on the
headlamp and dash wire harness connector locations.
(3) Remove all of the fasteners that secure each of
the headlamp and dash wire harness ground eyelets
to the vehicle body and chassis components. Refer to
Connector Locationsin Wiring for the location of
more information on the ground eyelet locations.
(4) Disengage each of the retainers that secure the
headlamp and dash wire harness to the vehicle body
and chassis components. Refer toConnector Loca-
tionsin Wiring for the location of more information
on the headlamp and dash wire harness retainer
locations.
(5) Unlatch and remove the cover from the PDC.
(6) Remove the screw that secures the engine wire
harness in-line connector to the PDC and disconnect
the connector (Fig. 8).
(7) Remove the nut that secures the eyelet of the
battery negative cable generator output take out to
the rearward B(+) terminal stud in the PDC and
remove the eyelet from the stud (Fig. 9).
(8) Remove the nut that secures the eyelet of the
battery positive cable PDC take out to the forward
B(+) terminal stud in the PDC and remove the eyelet
from the stud.
(9) Remove the screw that secures the PDC hous-
ing to the left front fender wheel housing (Fig. 10).(10) Remove the two screws that secure the PDC
housing to the left front fender inner shield.
(11) Remove the PDC and the headlamp and dash
wire harness from the engine compartment as a unit.
Fig. 8 Engine Wire Harness In-Line Connector
1 - LEFT FENDER
2 - POWER DISTRIBUTION CENTER
3 - ENGINE WIRE HARNESS IN-LINE CONNECTOR
4 - SCREW
Fig. 9 Battery and Generator Connections to PDC
1 - NUTS
2 - BATTERY POSITIVE CABLE
3 - BATTERY NEGATIVE CABLE
4 - POWER DISTRIBUTION CENTER
5 - CABLE EYELETS
Fig. 10 Power Distribution Center
1 - FENDER INNER SHIELD
2 - INNER WHEEL HOUSE
3 - SCREW
4 - SCREW
5 - POWER DISTRIBUTION CENTER
BR/BE8W-97 POWER DISTRIBUTION 8W - 97 - 9
POWER DISTRIBUTION CENTER (Continued)