2002 DODGE RAM hood open

INSTALLATION.........................22
MARKER LAMP
REMOVAL.............................23
INSTALLATION.........................23
MULTI-FUNCTION SWITCH
DESCRIPTION.........................23
OPERATION...........................24
DIAGNOSIS AND TESTING - MULTI-
FUNCTION SWITCH...................25
REMOVAL.............................27
INSTALLATION.........................28
OUTBOARD IDENTIFICATION LAMP
REMOVAL.............................28
INSTALLATION.........................29
PARK/TURN SIGNAL LAMP
REMOVAL.............................29
INSTALLATION.........................29
PARK/TURN SIGNAL LAMP UNIT
REMOVAL.............................29INSTALLATION.........................29
TAIL LAMP
DESCRIPTION.........................29
OPERATION...........................29
REMOVAL.............................29
INSTALLATION.........................30
TAIL LAMP UNIT
REMOVAL.............................30
INSTALLATION.........................30
TURN SIGNAL CANCEL CAM
DESCRIPTION.........................31
OPERATION...........................31
UNDERHOOD LAMP
REMOVAL.............................31
INSTALLATION.........................32
UNDERHOOD LAMP UNIT
REMOVAL.............................32
INSTALLATION.........................32
LAMPS/LIGHTING - EXTERIOR
DESCRIPTION - TURN SIGNAL & HAZARD
WARNING SYSTEM
A turn signal and hazard warning system is stan-
dard factory-installed safety equipment on this
model. The turn signal and hazard warning system
includes the following major components, which are
described in further detail elsewhere in this service
information:
²Combination Flasher- The electronic combi-
nation flasher is installed in the Junction Block (JB),
which is located behind the fuse access panel on the
left outboard end of the instrument panel.
²Hazard Warning Switch- The hazard warning
switch is integral to the multi-function switch on the
left side of the steering column. The hazard warning
switch button protrudes from a dedicated opening in
the shroud on the top of the steering column, just
below the steering wheel.
²Turn Signal Cancel Cam- The turn signal
cancel cam is integral to the clockspring, which is
located beneath the steering column shrouds at the
top of the steering column, just below the steering
wheel.
²Turn Signal Indicators- The two turn signal
indicators, one right and one left, are integral to the
ElectroMechanical Instrument Cluster (EMIC)
located in the instrument panel.
²Turn Signal Lamps- The front turn signal
lamps are integral to the lower front outboard ends
of the headlamp modules, located just outboard of the
two sides of the radiator grille opening. The rear
turn signal lamps are integral to the taillamp mod-
ules located on either side of the vehicle. For pickup
models the taillamp modules are secured to the rear
of the quarter panels at each side of the tailgateopening. For cab and chassis models the taillamp
modules are secured by a stamped steel bracket on
the outboard side of each frame rail near the rear of
the vehicle.
²Turn Signal Switch- The turn signal switch is
integral to the multi-function switch on the left side
of the steering column. The multi-function switch
control stalk that actuates the turn signal switch
protrudes from a dedicated opening in the steering
column shrouds on the left side of the column, just
below the steering wheel.
Hard wired circuitry connects the turn signal and
hazard warning system components to each other
through the electrical system of the vehicle. These
hard wired circuits are integral to several wire har-
nesses, which are routed throughout the vehicle and
retained by many different methods. These circuits
may be connected to each other, to the vehicle elec-
trical system and to the turn signal and hazard
warning system components through the use of a
combination of soldered splices, splice block connec-
tors and many different types of wire harness termi-
nal connectors and insulators. Refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
OPERATION - TURN SIGNAL & HAZARD
WARNING SYSTEM
The turn signal system operates on battery current
received on a fused ignition switch output (run-acc)
circuit so that the turn signals will only operate with
the ignition switch in the On or Accessory positions.
The hazard warning system operates on non-
8L - 2 LAMPS/LIGHTING - EXTERIORBR/BE

(9) Disconnect the instrument panel wire harness
connector for the multi-function switch from the
switch connector receptacle. Check for continuity
between the hazard flasher signal circuit cavities in
the JB receptacle for the combination flasher and the
instrument panel wire harness connector for the
multi-function switch. There should be continuity. If
OK, go to Step 10. If not OK, repair the open hazard
flasher signal circuit between the JB and the multi-
function switch as required.
(10) Check for continuity between the flasher out-
put circuit cavities of the JB receptacle for the com-
bination flasher and in the instrument panel wire
harness connector for the multi-function switch.
There should be continuity. If OK, test the multi-
function switch. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/MULTI-FUNCTION
SWITCH - DIAGNOSIS AND TESTING). If not OK,
repair the open flasher output circuit between the JB
and the multi-function switch as required.
SPECIFICATIONS
EXTERIOR LAMPS
LAMP BULB
Back-up 3157
Cargo 921
Center High Mounted
Stop921
Clearance Roof Mounted 168
Fog Lamps 896
Headlamp - SLT 9004LL
Headlamp - Sport Low
Beam9007
Headlamp - Sport High
Beam9004LL
License Plate w/o
Bumper1155
License Plate -Step
Bumper168
Park/Turn Signal 3157NA
Snow Plow Control 161
Tail/Brake/Turn Signal 3157
Tail/Brake/Cab - Chassis 1157
Underhood 105
SPECIAL TOOLS
HEADLAMP ALIGNMENT
BRAKE LAMP SWITCH
DESCRIPTION
The plunger type brake lamp switch is mounted on
a bracket attached to the brake pedal support under
the instrument panel.
CAUTION: The switch can only be adjusted during
initial installation. If the switch is not adjusted prop-
erly a new switch must be installed.
OPERATION
The brake lamp switch is used for the brake lamp,
speed control brake sensor circuits and electronic
brake distribution (EBD). The brake lamp circuit is
open until the plunger is depressed. The speed con-
trol and brake sensor circuits are closed until the
plunger is depressed.
When the brake light switch is activated, the Pow-
ertrain Control Module (PCM) receives an input indi-
cating that the brakes are being applied. After
receiving this input, the PCM maintains idle speed to
a scheduled rpm through control of the Idle Air Con-
trol (IAC) motor. The brake switch input is also used
to disable vent and vacuum solenoid output signals
to the speed control servo.
Vehicles equipped with the speed control option use
a dual function brake lamp switch. The PCM moni-
tors the state of the dual function brake lamp switch.
Refer to the Brake section for more information on
brake lamp switch service and adjustment proce-
dures.
Headlamp Aiming Kit C-4466±A
8L - 4 LAMPS/LIGHTING - EXTERIORBR/BE
LAMPS/LIGHTING - EXTERIOR (Continued)

AMBIENT TEMP SENSOR
DESCRIPTION
Ambient air temperature is monitored by the com-
pass mini-trip computer module through the ambient
temperature sensor. The ambient temperature sensor
is a variable resistor mounted to a bracket that is
secured with a screw to the underside of the hood
panel near the hood latch striker in the engine com-
partment (Fig. 8).
For complete circuit diagrams, refer toOverhead
Consolein the Contents of Wiring Diagrams. The
ambient temperature sensor cannot be adjusted or
repaired and, if faulty or damaged, it must be
replaced.
OPERATION
The ambient temperature sensor is a variable
resistor that operates on a five-volt reference signal
sent to it by the compass mini-trip computer module.
The resistance in the sensor changes as temperature
changes, changing the return circuit voltage to the
compass mini-trip computer module. Based upon the
resistance in the sensor, the compass mini-trip com-
puter module senses a specific voltage on the return
circuit, which it is programmed to correspond to a
specific temperature.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR
The thermometer function is supported by the
ambient temperature sensor, a wiring circuit, and a
portion of the compass mini-trip computer module. If
any portion of the ambient temperature sensor cir-
cuit fails, the compass/thermometer display function
will self-diagnose the circuit. If 55É C (131É F)
appears in the display, the sensor is being exposed to
temperatures above 55É C (131É F), or the sensor cir-
cuit is shorted. If ±40É C (±40É F) appears in the dis-
play, the sensor is being exposed to temperatures
below ±40É C (±40É F), or the sensor circuit is open.
The ambient temperature sensor circuit can also be
diagnosed using the following Sensor Test, and Sen-
sor Circuit Test. If the temperature sensor and cir-
cuit are confirmed to be OK, but the temperature
display is inoperative or incorrect, refer toDiagnosis
and Testing the Compass Mini-Trip Computer.
For complete circuit diagrams, refer toWiring Dia-
grams.
SENSOR TEST
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector.(2) Measure the resistance of the ambient temper-
ature sensor. At ±40É C (±40É F), the sensor resis-
tance is 336 kilohms. At 55É C (131É F), the sensor
resistance is 2.488 kilohms. The sensor resistance
should read between these two values. If OK, refer to
theSensor Circuit Test below. If not OK, replace
the faulty ambient temperature sensor.
SENSOR CIRCUIT TEST
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector and the overhead console wire har-
ness connector.
(2) Connect a jumper wire between the two termi-
nals in the body half of the ambient temperature sen-
sor wire harness connector.
(3) Check for continuity between the sensor return
circuit and the ambient temperature sensor signal
circuit cavities of the roof wire harness overhead con-
sole connector. There should be continuity. If OK, go
to Step 4. If not OK, repair the open sensor return
circuit or ambient temperature sensor signal circuit
to the ambient temperature sensor as required.
(4) Remove the jumper wire from the body half of
the ambient temperature sensor wire harness con-
nector. Check for continuity between the sensor
return circuit cavity of the roof wire harness over-
head console connector and a good ground. There
should be no continuity. If OK, go to Step 5. If not
OK, repair the shorted sensor return circuit as
required.
(5) Check for continuity between the ambient tem-
perature sensor signal circuit cavity of the roof wire
harness overhead console connector and a good
ground. There should be no continuity. If OK, refer to
Diagnosis and Testing the Compass Mini-Trip
Computerin this section. If not OK, repair the
shorted ambient temperature sensor signal circuit as
required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Locate the ambient temperature sensor, on the
underside of the hood near the hood latch striker
(Fig. 8).
(3) Disconnect the wire harness connector from the
ambient temperature sensor connector receptacle.
(4) Remove the one screw that secures the ambient
temperature sensor bracket to the inner hood rein-
forcement.
(5) Remove the ambient temperature sensor from
the inner hood reinforcement.
8M - 12 MESSAGE SYSTEMSBR/BE

proper wiper blade travel on the glass. The socket
formation with internal serrations in the wiper arm
pivot end interlocks with the serrations on the outer
circumference of the wiper pivot driver, allowing pos-
itive engagement and finite adjustment of this con-
nection. The latch plate on the underside of the
wiper arm pivot end locks the wiper arm to the wiper
pivot when in its installed position and, when in its
unlocked position, also serves as a blocker to hold the
spring-loaded wiper arm off of the glass to facilitate
removal and installation. The spring-loaded wiper
arm hinge controls the down-force applied through
the tip of the wiper arm to the wiper blade on the
glass. The hook formation on the tip of the wiper arm
provides a cradle for securing and latching the wiper
blade pivot block to the wiper arm.
REMOVAL
(1) Unlatch and open the hood.
(2) Lift the wiper arm far enough to raise the
wiper blade off of the glass and permit the wiper arm
latch plate to be pulled out to its holding position,
then release the arm (Fig. 5). The wiper arm and
blade will remain off the glass with the latch in this
position.
CAUTION: The use of a screwdriver or other prying
tool to remove a wiper arm may distort it. This dis-
tortion could allow the arm to come off of the wiper
pivot during wiper operation, regardless of how
carefully it is reinstalled.
(3) Using a slight rocking motion, remove the
wiper arm pivot end from the wiper pivot.
INSTALLATION
NOTE: Be certain that the wiper motor is in the park
position before attempting to install the wiper arms.
Turn the ignition switch to the On position and
move the wiper control knob on the end of the
multi-function switch control stalk to its Off posi-
tion. If the wiper pivots move, wait until they stop
moving, then turn the ignition switch back to theOff position. The wiper motor is now in its park
position.
(1) The wiper arms must be indexed to the wiper
pivots with the wiper motor in the park position to
be properly installed (Fig. 6). Position the wiper arm
pivot ends onto the wiper pivots so that the lower
edge of the wiper arm tip is on the upper edge of the
lower windshield blackout area   22 millimeters ( 
0.86 inches).
(2) Once the wiper arm is indexed to the wiper
pivot, lift the wiper arm away from the windshield
slightly to relieve the spring tension on the latch
plate, then push the latch plate into the locked posi-
tion. Gently lower the wiper arm until the wiper
blade rests on the glass.
(3) Wet the windshield glass, then operate the wip-
ers. Turn the wiper control knob on the end of the
multi-function switch control stalk to the Off posi-
tion, then check for the correct wiper arm position
and adjust as required.
WIPER BLADE
DESCRIPTION
Each wiper blade is secured by an integral latching
pivot block to the hook formation on the tip of the
wiper arms, and rests on the glass near the base of
the windshield when the wipers are not in operation.
The wiper blade consists of the following components:
²Superstructure- The superstructure includes
several stamped steel bridges and links with claw
formations that grip the wiper blade element. Also
included in this unit is the latching, molded plastic
pivot block that secures the superstructure to the
wiper arm. All of the metal components of the wiper
blade have a satin black finish applied.
²Element- The wiper element or squeegee is the
resilient rubber member of the wiper blade that con-
tacts the glass.
²Flexor- The flexor is a rigid metal component
running along the length of each side of the wiper
element where it is gripped by the claws of the
superstructure.Fig. 5 Wiper Arm Remove/Install - Typical
Fig. 6 Wiper Arm Installation
8R - 12 WIPERS/WASHERSBR/BE
WIPER ARM (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)

FRONT AIR DAM
REMOVAL
(1) Remove Pin-type fasteners attaching air dam
to bottom of front bumper (Fig. 1).
(2) Remove screws attaching air dam to bottom of
front bumper.
(3) Separate air dam from bumper.
INSTALLATION
(1) Position air dam on bumper.
(2) Install screws attaching air dam to bottom of
front bumper.
(3) Install Pin-type fasteners attaching air dam to
bottom of front bumper.
FRONT FASCIA
REMOVAL
(1) Open hood.
(2) Remove fasteners at fender side openings.
(3) Separate fascia from bumper.
INSTALLATION
(1) Position fascia on bumper.
(2) Install front fascia. See fascia adjustment pro-
cedure in this section.
(3) Install fasteners at fender side openings.
ADJUSTMENTS
ADJUSTMENT
(1) Remove the plastic rivet that secures the front
upper fascia to the front lower fascia (Fig. 2).
(2) Position the upper front fascia so that there is
approximately a 19 mm (3/4 in.) gap between the
lower portion of the front fender and the upper por-
tion of the front upper fascia (Fig. 3). The gap should
ideally be 19 mm (3/4 in.), but it is more important to
avoid a V-Gap between the lower portion of the front
fender and the upper portion of the front upper fas-
cia than maintaining the gap. There are ribs in the
front upper fascia and lower fascia that will hold the
front upper fascia in position (Fig. 4).
(3) Attach the front upper fascia to the front lower
fascia using a new plastic rivet.
Fig. 1 Front Bumper Air Dam
1 - BUMPER
2 - SCREW
3 - LOWER AIR DAM
4 - PIN TYPE FASTENER
5 - LOWER FASCIA
Fig. 2 Fascia Rivet
1 - RIVET MUST BE REPLACED AFTER EACH ADJUSTMENT
13 - 2 FRAME & BUMPERSBR/BE

FRONT LOWER FASCIA
REMOVAL
(1) Open hood.
(2) Remove fasteners at side fender openings.
(3) Remove lower air dam.(Refer to 13 - FRAMES
& BUMPERS/BUMPERS/FRONT AIR DAM -
REMOVAL)
(4) Disengage clips attaching end of upper fascia to
bumper face bar (Fig. 5).
(5) Disengage clips attaching lower fascia to
bumper face bar.
(6) Separate lower fascia from bumper.
INSTALLATION
(1) Position lower fascia on bumper.
(2) Engage clips attaching lower fascia to bumper
face bar.
(3) Install lower air dam.(Refer to 13 - FRAMES &
BUMPERS/BUMPERS/FRONT AIR DAM - INSTAL-
LATION)
(4) Install fasteners at side fender openings.
FRONT FASCIA - SPORT
REMOVAL
The fascia can be removed from the vehicle without
removing the bumper.
(1) Disconnect wire connectors from fog lamps.
(2) Remove screws attaching rearward edges of
fascia to outer bumper brackets (Fig. 7) .
(3) Remove screws attaching bottom of air deflec-
tor.
(4) Lift top of fascia upward to disengage from
retaining clips on front bumper.
(5) Pull fascia from front bumper and separate
from vehicle.
INSTALLATION
(1) Position fascia on front bumper.
(2) Engage fascia with retaining clips on front
bumper.
Fig. 3 Fascia Gap
1 - GAP Ð 19 mm PARALLELISM MOST IMPORTANT
Fig. 4 Fascia Adjustment Ribs
1 - FRONT UPPER FASCIA
2 - ADJUSTMENT RIBS
3 - FRONT LOWER FASCIA
Fig. 5 Front Bumper Lower Fascia
1 - LOWER FASCIA
2 - RETAINING CLIP
3 - BUMPER
BR/BEFRAME & BUMPERS 13 - 3
FRONT FASCIA (Continued)