2002 DODGE RAM fuse

The Integrated Circuitry (IC) within the combina-
tion flasher (Fig. 6) contains the logic that controls
the flasher operation and the flash rate. Pin 6 of the
IC receives a sense voltage from the hazard warning
circuit of the multi-function switch. When the hazard
warning switch is turned on, the9hazard on sense9
voltage will become low due to the circuit being
grounded through the turn signal bulbs. This low
voltage sense signals the IC to energize the flash con-
trol Positive-Negative-Positive (PNP) transistor at a
pre-calibrated flash rate or frequency. Each time the
PNP transistor energizes the hazard warning circuit,
the pin 69hazard on sense9voltage will become high
and the IC signals the PNP transistor to de-energize
the circuit. This cycling will continue until the haz-
ard warning switch is turned off.
Likewise, pin 8 of the IC receives a sense voltage
from the turn signal circuits of the multi-function
switch. When the left or right turn signal switch is
turned on, the9turn signal on sense9voltage will
become low due to the circuit being grounded
through the turn signal bulbs. This low voltage sense
signals the IC to energize the flash control PNP tran-
sistor at a pre-calibrated flash rate or frequency.
Each time the PNP transistor energizes the turn sig-
nal circuit, the pin 89turn signal on sense9voltage
will become high and the IC signals the PNP transis-
tor to de-energize the circuit. This cycling will con-
tinue until the right or left turn signal switch is
turned off.A special design feature of the combination flasher
allows it to9sense9that a turn signal circuit or bulb
is not operating, and provide the driver an indication
of the condition by flashing the remaining bulbs in
the affected circuit at a higher rate (120 flashes-per-
minute or higher). Conventional flashers either con-
tinue flashing at their typical rate (heavy-duty type),
or discontinue flashing the affected circuit entirely
(standard-duty type). During turn signal operation,
the combination flasher IC compares normal battery
voltage input on pin 2 with the shunt resistor voltage
input on pin 7. If the IC9senses9that the voltage dif-
ference between pin 2 and pin 7 is different than the
pre-calibrated value of the IC, it will increase the
rate at which it signals the PNP transistor to ener-
gize the pin 1 output. Thus, the inoperative half (left
or right side) of the turn signal circuit will flash
faster.
Because of the active electronic elements within
the combination flasher, it cannot be tested with con-
ventional automotive electrical test equipment. If the
combination flasher is believed to be faulty, test the
turn signal system and hazard warning system. Then
replace the combination flasher with a known good
unit to confirm system operation. (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/TURN
SIGNAL & HAZARD WARNING SYSTEM - DIAG-
NOSIS AND TESTING).
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the fuse access panel by unsnapping it
from the left outboard end of the instrument panel.
(3) Remove the combination flasher from the Junc-
tion Block (JB) (Fig. 7).
Fig. 6 Combination Flasher - Typical
8L - 8 LAMPS/LIGHTING - EXTERIORBR/BE
COMBINATION FLASHER (Continued)

INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Position the combination flasher in the proper
receptacle of the Junction Block (JB).
(2) Align the terminals of the combination flasher
with the terminal cavities in the JB receptacle for
the flasher.
(3) Push in firmly and evenly on the combination
flasher until the terminals are fully seated in the ter-
minal cavities of the JB receptacle for the flasher.
(4) Reinstall the fuse access panel by snapping it
onto the left outboard end of the instrument panel.
(5) Reconnect the battery negative cable.
DAYTIME RUNNING LAMP
MODULE
DESCRIPTION
The Daytime Running Lights (Headlamps) System
is installed on vehicles manufactured for sale in Can-
ada only. A separate module, mounted on the cowl,
controls the DRL.
OPERATION
The headlamps are illuminated when the ignition
switch is turned to the ON position. The DRL module
receives a vehicle-moving signal from the vehicle
speed sensor. This provides a constanthead-
lamps-oncondition as long as the vehicle is moving.
The lamps are illuminated at less than 50 percent of
normal intensity.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disengage wire connector from DRLM (Fig. 8).
(3) Remove screws attaching DRLM to left front
inner fender panel.
(4) Separate DRLM from fender.
INSTALLATION
(1) Position DRLM on fender.
(2) Install screws attaching DRLM to left front
inner fender panel.
(3) Engage wire connector to DRLM.
(4) Connect the battery negative cable.
Fig. 7 Junction Block
1 - JUNCTION BLOCK
2 - FUSE ACCESS PANEL
Fig. 8 Daytime Running Lamp Module (DRLM)
1 - HEADLAMP AND DASH WIRING HARNESS
2 - LEFT FENDER SIDE SHIELD
3 - DAYTIME RUNNING LAMP MODULE
BR/BELAMPS/LIGHTING - EXTERIOR 8L - 9
COMBINATION FLASHER (Continued)

FOG LAMP
DIAGNOSIS AND TESTING - FOG LAMP
CONDITION POSSIBLE CAUSES CORRECTION
FOG LAMPS ARE DIM
WITH ENGINE IDLING OR
IGNITION TURNED OFF.1. Loose or corroded battery cables. 1. Clean and secure battery cable clamps
and posts.
2. Loose or worn generator drive
belt.2. Adjust or replace generator drive belt.
3. Charging system output too low. 3. Test and repair charging system.
4. Battery has insufficient charge. 4. Test battery state-of -charge.
5. Battery is sulfated or shorted. 5. Load test battery.
6. Poor lighting circuit Z33-ground. 6. Test for voltage drop across Z33-ground
locations.
FOG LAMP BULBS BURN
OUT FREQUENTLY1. Charging system output too high. 1. Test and repair charging system.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and
splices.
FOG LAMPS ARE DIM
WITH ENGINE RUNNING
ABOVE IDLE1. Charging system output too low. 1. Test and repair charging system.
2. Poor lighting circuit Z33-ground. 2. Test for voltage drop across Z33-ground
locations.
3. High resistance in fog lamp circuit. 3. Test amperage draw of fog lamp circuit.
FOG LAMPS FLASH
RANDOMLY1. Poor lighting circuit Z33-ground. 1. Test for voltage drop across Z33-ground
locations.
2. High resistance in fog lamp circuit. 2. Test amperage draw of fog lamp circuit.
3. Faulty fog lamp switch. 3. Replace fog lamp switch.
4. Loose or corroded terminals or
splices in circuit.4. Inspect and repair all connectors and
splices.
FOG LAMPS DO NOT
ILLUMINATE1. Blown fuse for fog lamp. 1.Trace short and replace fuse.
2. No Z33-ground at fog lamps. 2. Repair circuit ground.
3. Faulty fog lamp switch. 3. Replace fog lamp switch.
4. Broken connector terminal or wire
splice in fog lamp circuit.4. Repair connector terminal or wire splice.
5. Defective or burned out bulb. 5. Replace bulb.
FOG LAMPS ARE
INOPERATIVE AND FOG
LAMP INDICATOR LIGHT
ALWAYS STAYS ON.1. Fog lamp/DRL* feed shorted to
ground.1. Check wiring circuit from fog lamp/DRL*
fuse to fog lamp. Trace short circuit in
wiring and repair.
FOG LAMPS ARE
INOPERATIVE AND FOG
LAMP INDICATOR LIGHT
IS ILLUMINATED.1. Fog lamp/DRL* fuse defective. 1. Trace short circuit and replace fuse.
2. Open circuit from fog lamp fuse to
fog lamp.2. Check wiring circuit from fog lamp/DRL*
fuse to fog lamp. Trace open circuit in
wiring and repair.
8L - 10 LAMPS/LIGHTING - EXTERIORBR/BE

CONDITION POSSIBLE CAUSES CORRECTION
PARK LAMPS ARE
INOPERATIVE. FOG LAMP
INDICATOR IS ON WHEN
ALL SWITCHES ARE OFF
AND FUNCTIONS
OPPOSITE TO FOG
LAMPS.1. Park lamp feed is shorted. 1. Check wiring circuit from park lamp fuse
to headlamp switch. Trace short circuit in
wiring and repair.
PARK LAMPS ARE
INOPERATIVE. FOG LAMP
INDICATOR FUNCTIONS
OPPOSITE TO FOG
LAMPS.1. Park lamp fuse is defective. 1. Trace short circuit and replace fuse.
2. Open circuit from park lamp fuse
to headlamp switch.2. Check wiring circuit from park lamp fuse
to headlamp switch. Trace open circuit in
wiring and repair.
*Canada vehicles use Daytime Running Lamps (DRL).
Additional fog lamp diagnostic procedures listed are for vehicles equipped with quad headlamps and the
DRL option.
CONDITION POSSIBLE CAUSES CORRECTION
FOG LAMPS ARE INOPERATIVE
AND FOG LAMP INDICATOR
S TAY S A LWAY S O N .1 Fog lamp/DRL* feed shorted to
ground.1. Check wiring circuit from fog
lamp/DRL* fuse to fog lamp.Trace
short circuit in wiring and repair.
FOG LAMP INDICATOR COMES
ON WITH OUT ILLUMINATING THE
FOG LAMPS1. Fog lamp/DRL* fuse defective. 1. Trace short circuit and replace
fuse.
FOG LAMPS INOPERATIVE WITH
INGNITION OFF.Open circuit from fog lamp fuse to
fog lamp.1. Check wiring circuit from fog
lamp/DRL* fuse to fog lamp. Trace
open circuit in wiring and repair.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disengage fog lamp harness connector.
(3) Rotate bulb assembly counterclockwise and
pull from lamp to separate (Fig. 9).
INSTALLATION
CAUTION: Do not touch the bulb glass with fingers
or other oily surfaces. Reduced bulb life will result.
(1) Position bulb assembly in lamp and rotate
clockwise.
(2) Connect fog lamp harness connector.
(3) Connect the battery negative cable.
BR/BELAMPS/LIGHTING - EXTERIOR 8L - 11
FOG LAMP (Continued)

DIAGNOSIS AND TESTING - HEADLAMP
A good ground is necessary for proper lighting
operation. Grounding is provided by the lamp socket
when it comes in contact with the metal body, or
through a separate ground wire.
Always begin any diagnosis by testing all of the
fuses and circuit breakers in the system. For com-plete circuit diagrams, refer to the appropriate wir-
ing 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.
CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMPS ARE DIM
WITH ENGINE IDLING1. Loose or corroded battery cables. 1. Clean and secure battery cable clamps
and posts.
OR IGNITION TURNED
OFF2. Loose or worn generator drive
belt.2. Adjust or replace generator drive belt.
3. Charging system output too low. 3. Test and repair charging system.
4. Battery has insufficient charge. 4. Test battery state-of -charge.
5. Battery is sulfated or shorted. 5. Load test battery.
6. Poor lighting circuit Z3-ground. 6. Test for voltage drop across Z3-ground
locations.
7. Both headlamp bulbs defective. 7. Replace both headlamp bulbs.
HEADLAMP BULBS BURN
OUT1. Charging system output too high. 1. Test and repair charging system.
FREQUENTLY 2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and
splices.
HEADLAMPS ARE DIM
WITH ENGINE RUNNING1. Charging system output too low. 1. Test and repair charging system.
ABOVE IDLE* 2. Poor lighting circuit Z3-ground. 2. Test for voltage drop across Z3-ground
locations.
3. High resistance in headlamp
circuit.3. Test amperage draw of headlamp circuit.
4. Both headlamp bulbs defective. 4. Replace both headlamp bulbs.
HEADLAMPS FLASH
RANDOMLY1. Poor lighting circuit Z3-ground. 1. Test for voltage drop across Z3-ground
locations.
2. High resistance in headlamp
circuit.2. Test amperage draw of headlamp circuit.
Should not exceed 30 amps.
3. Faulty headlamps switch circuit
breaker.3. Replace headlamp switch.
4. Loose or corroded terminals or
splices in circuit.4. Inspect and repair all connectors and
splices.
HEADLAMPS (HIGH &
LOW) DO NOT
ILLUMINATE1. No voltage at either headlamp. 1. Voltage should always be present. Trace
short circuit and replace BOTH headlamp
fuses. Check wiring circuit from Right
headlamp fuse to headlamp. (Repeat for
Left side)
8L - 14 LAMPS/LIGHTING - EXTERIORBR/BE
HEADLAMP (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
2. No ground for high and low beam
circuit.2. Ground should always be present
according to switch position. Check ground
at headlamp switch. Check wiring circuit
from headlamp switch to Multifunction
switch. Check headlamp switch and
Multifunction switch continuity. Repair circuit
ground.
3. Headlamp bulb(s) defective. 3. Replace bulb(s).
4. Faulty headlamp switch. 4. Replace headlamp switch.
5. Faulty headlamp dimmer
(Multifunction) switch.5. Replace Multifunction switch.
6. Broken connector terminal or wire
splice in headlamp circuit.6. Repair connector terminal or wire splice.
HEADLAMPS (LOW
BEAM) DO NOT
ILLUMINATE.1. No ground for low beam circuit. 1. Ground should be present according to
Multifunction switch position. Check wiring
circuit from Multifunction switch to
headlamp. Trace open circuit in wiring and
repair.
Check Multifunction Switch for continuity.
HEADLAMPS (HIGH
BEAM) DO NOT
ILLUMINATE.1. No ground for high beam circuit. 1. Ground should be present according to
Multifunction switch position. Check wiring
circuit from Multifunction switch to
headlamp . Trace open circuit in wiring and
repair.
Check Multifunction Switch for continuity.
HEADLAMPS (LOW
BEAM) ALWAYS
ILLUMINATE AND CAN
NOT BE SHUT OFF.1. Low beam circuit from bulb to
Multifunction switch is shorted to
ground.1. Ground should be present according to
Multifunction switch position. Check wiring
circuit from Multifunction switch to
headlamp. Trace short circuit in wiring and
repair.
HEADLAMPS (HIGH
BEAM) ALWAYS
ILLUMINATE AND CAN
NOT BE SHUT OFF.1. High beam circuit from bulb to
Multifunction switch is shorted to
ground.1. Ground should be present according to
Multifunction switch position. Check wiring
circuit from Multifunction switch to
headlamp. Trace short circuit in wiring and
repair.
QUAD LAMPS DO NOT
ILLUMINATE AND HIGH
BEAMS ILLUMINATE.1. No voltage at either headlamp. 1. Voltage should always be present. Check
Quad lamp fuse. Check wiring circuit from
Quad lamp fuse to Quad lamp. Repeat for
left side
2. No ground for Quad beam circuit. 2. Ground should be present according to
Multifunction switch position. Check ground
at quad lamp relay. Check for battery
voltage at quad lamp relay. Check quad
lamp relay. Check relay control circuit (relay
coil to high beam).
3. If voltage and ground are present,
bulb(s) is defective.3.
Replace bulb(s).
BR/BELAMPS/LIGHTING - EXTERIOR 8L - 15
HEADLAMP (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMP SWITCH OFF
HEADLAMPS AND
HIGHBEAM INDICATOR
REMAIN ON AND ARE
DIM.1. Headlamp switch feed circuit
shorted to ground.1. Check wiring circuit from right headlamp
fuse to headlamp. Repeat for left side.
Trace short circuit in wiring and repair.
HEADLAMP SWITCH ON
(LOW BEAMS ON), ONE
LOW BEAM ON AND
BOTH HIGH BEAMS DIM.1. Headlamp feed circuit shorted to
ground.1. Check wiring circuit from right headlamp
fuse to headlamp. Repeat for left side.
Trace short circuit in wiring and repair.
HEADLAMP SWITCH ON
(HIGH BEAMS ON), ONE
HIGH BEAM ON AND
BOTH LOW BEAMS DIM.1. Headlamp feed circuit shorted to
ground.1. Check wiring circuit from right headlamp
fuse to headlamp. Repeat for left side.
Trace short circuit in wiring and repair.
HEADLAMP SWITCH ON,
ONE HEADLAMP
FILAMENT WILL BE AT
FULL INTENSITY AND ALL
OTHER FILAMENTS ARE
ON AND DIM.1. Blown headlamp fuse. 1. Trace short circuit and replace fuse.
2. Open circuit from headlamp fuse
to headlamp.2. Repair open headlamp circuit.
1. HEADLAMPS STAY ON
WITH KEY OUT (DRLM
EQUIPPED VEHICLES).1. Failed DRLM 1. Replace DRLM.
*Canada vehicles must have lamps ON.
REMOVAL
On the driver side, the battery and battery tray
must be removed to service the headlamp bulb.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the battery tray (Refer to 8 - ELEC-
TRICAL/BATTERY SYSTEM/TRAY - REMOVAL).
(3) Disengage wire connector from headlamp
bulb(s).
(4) Remove retaining ring holding bulb(s) to head-
lamp (Fig. 13).
(5) Pull bulb(s) from headlamp.
INSTALLATION
CAUTION: Do not touch the bulb glass with fingers
or other oily surfaces. Reduced bulb life will result.
(1) Position bulb(s) in headlamp.
(2) Install retaining ring holding bulb(s) to head-
lamp.
(3) Connect wire connector to headlamp bulb(s).(4) Install battery tray, if removed (Refer to 8 -
ELECTRICAL/BATTERY SYSTEM/TRAY - INSTAL-
LATION).
(5) Connect battery negative cable.
Fig. 13 Headlamp Bulb
1 - BULB SOCKET
2 - BULB ASSEMBLY
3 - LOCK
4 - BULB RETAINING RING
5 - ELECTRICAL CONNECTOR
6 - UNLOCK
7 - PLASTIC BASE
8L - 16 LAMPS/LIGHTING - EXTERIORBR/BE
HEADLAMP (Continued)

HEADLAMP RELAY
DESCRIPTION
The headlamp (or security) relay is located in the
Power Distribution Center (PDC) near the battery in
the engine compartment (Fig. 14). See the fuse and
relay layout label affixed to the inside surface of the
PDC cover for headlamp relay identification and loca-
tion. The headlamp relay is a conventional Interna-
tional Standards Organization (ISO) micro relay.
Relays conforming to the ISO specifications have
common physical dimensions, current capacities, ter-
minal patterns, and terminal functions. The relay is
contained within a small, rectangular, molded plastic
housing. The relay is connected to all of the required
inputs and outputs through its PDC receptacle by
five male spade-type terminals that extend from the
bottom of the relay base. The ISO designation for
each terminal is molded into the base adjacent to the
terminal. The ISO terminal designations are as fol-
lows:
²30 (Common Feed)- This terminal is con-
nected to the movable contact point of the relay.
²85 (Coil Ground)- This terminal is connected
to the ground feed side of the relay control coil.
²86 (Coil Battery)- This terminal is connected
to the battery feed side of the relay control coil.
²87 (Normally Open)- This terminal is con-
nected to the normally open fixed contact point of the
relay.
²87A (Normally Closed)- This terminal is con-
nected to the normally closed fixed contact point of
the relay.
The headlamp relay cannot be adjusted or
repaired. If the relay is damaged or faulty, it must be
replaced.
OPERATION
The headlamp (or security) relay is an electrome-
chanical switch that uses a low current input from
the high-line or premium Central Timer Module
(CTM) to control a high current output to the head-
lamps. 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 wind-
ings. 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 or diode is connected in par-
allel with the relay coil in the relay, and helps to dis-
sipate voltage spikes and electromagnetic
interference that can be generated as the electromag-
netic field of the relay coil collapses.
The headlamp relay terminals are connected to the
vehicle electrical system through a connector recepta-
cle in the Power Distribution Center (PDC). The
inputs and outputs of the headlamp relay include:
²The common feed terminal (30) is connected to
ground at all times through a take out and eyelet
terminal connector of the right headlamp and dash
wire harness that is secured by a ground screw to
the left fender inner shield near the PDC in the
engine compartment.
²The coil ground terminal (85) is connected to the
Central Timer Module (CTM) through the security
relay control circuit. The CTM energizes the head-
lamp relay control coil by internally pulling this cir-
cuit to ground.
²The coil battery terminal (86) is connected to
battery current at all times through a fused B(+) cir-
cuit that is internal to the PDC.
²The normally open terminal (87) is connected to
the headlamps at all times through the beam select
switch low beam output circuit. This circuit provides
a path to ground for the headlamps through the com-
mon feed terminal when the headlamp relay control
coil is energized by the CTM.
²The normally closed terminal (87A) is not con-
nected to any circuit in this application, but is
grounded through the common feed terminal when
the headlamp relay control coil is de-energized.
The headlamp relay can be diagnosed using con-
ventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - HEADLAMP RELAY
The headlamp (or security) relay (Fig. 15) is
located in the Power Distribution Center (PDC) near
the battery in the engine compartment. See the fuse
and relay layout label affixed to the inside surface of
Fig. 14 Power Distribution Center
1 - COVER
2 - POWER DISTRIBUTION CENTER
BR/BELAMPS/LIGHTING - EXTERIOR 8L - 17