relay JEEP XJ 1995 Service And Repair Manual

INSTRUMENT CLUSTER
INSTRUMENT CLUSTER
The instrument cluster contains the gauges and
warning lamps. All gauges have magnetic move-
ments.
When the ignition switch is in either the START or
RUN position, circuit A1 from fuse 4 in the Power
Distribution Center (PDC) connects to circuit A21.
Circuit A21 powers fuse 9 in the fuse block. Fuse 9
powers circuit G5. One branch of circuit G5 connects
directly to the combination buzzer. The other branch
of circuit G5 splices to power the gauges, speedome-
ter, tachometer, voltmeter, indicator lamps, and
warning lamps in the instrument cluster.
When the parking lamps or headlamps are ON, the
headlamp switch connects circuit F33 to circuit L7.
Circuit L7 splices to the dimmer switch. Circuit E1
from the dimmer switch powers fuse 10 in the fuse
block when the parking lamps or headlamps are ON.
Circuit E2 from fuse 10 in the fuse block feeds the
illumination lamps in the instrument cluster.
Circuit Z1 provides ground the instrument cluster
illumination lamps, gauges and warning lamps.
HELPFUL INFORMATION
²Circuit G5 also powers the heated rear window,
A/C compressor clutch relay. On Canadian vehicles,
circuit G5 powers the Daytime Running Lamps
(DRL) module.
²Circuit F33 originates at fuse 8 in the fuse block.
Circuit A6 from fuse 3 in the PDC powers fuse 8 in
the fuse block.
ENGINE COOLANT TEMPERATURE GAUGE
Circuit G20 connects the engine coolant tempera-
ture gauge to the engine coolant temperature sensor.
The sensor is a variable resistor and case grounded
to the engine. Circuit G5 connects to the instrument
cluster and supplies voltage for the gauge.
The gauge uses two coils. The first coil has fixed
current flowing through it to maintain magnetic field
strength. Circuit Z1 provides ground for the fixed
current coil. The current level passing through the
second coil is controlled by the variable resistor in
the engine coolant temperature sender. The changing
current varies the magnetic field in the second coil.
Refer to group 8E, Instrument Panel and Gauges
for gauge operation.
FUEL GAUGE
Circuit G4 connects the fuel level sensor to the fuel
gauge in the instrument cluster. Circuit G5 supplies
voltage to the fuel gauge. The fuel level sensor draws
voltage from circuit G5 through the fuel gauge on cir-
cuit G4.The gauge uses two coils. The first coil has fixed
current flowing through it to maintain magnetic field
strength. Circuit Z1 provides ground for the fixed
current coil. The current level passing through the
second coil is controlled by the variable resistor in
the fuel level sensor. The changing current varies the
magnetic field in the second coil.
Circuit Z2 provides the ground path for the fuel
level sensor.
Refer to group 8E, Instrument Panel and Gauges
for gauge operation.
OIL PRESSURE GAUGE
The case grounded oil pressure sending unit is a
variable resistor. The sending unit connects to the oil
pressure gauge on circuit G60.
Circuit G5 connects to the instrument cluster and
supplies battery voltage to the oil pressure gauge.
The gauge uses two coils. The first coil has fixed cur-
rent flowing through it to maintain magnetic field
strength. Circuit Z1 provides ground for the fixed
current coil. The current level passing through the
second coil is controlled by the variable resistor in
the oil pressure sending unit. The changing current
varies the magnetic field in the second coil.
Refer to group 8E, Instrument Panel and Gauges
for gauge operation.
TACHOMETER
The Powertrain Control Module (PCM) provides
the tachometer signal to the electronic tachometer on
circuit G21. Circuit G21 originates at cavity 43 of the
PCM. Circuit Z1 provides ground for the tachometer's
internal logic circuits.
SPEEDOMETER
The electronic speedometer and odometer receive a
signal from the vehicle speed sensor on circuit G7.
Circuit G5 connects to the instrument cluster and
supplies battery voltage to the speedometer. Circuit
Z1 provides ground for the speedometer internal logic
circuits.
Circuit G7 splices to connect to the Powertrain
Control Module (PCM) and if equipped, the Daytime
Running Lamps (DRL) module.
FOUR-WHEEL DRIVE (4WD) INDICATOR LAMP
When the 4WD switch closes, circuit Z1 provides
ground for the 4WD indicator lamp in the instrument
panel. Circuit G5 connects to the instrument cluster
and supplies battery voltage to the 4WD indicator
lamp. Circuit G1 connects the indicator lamp to the
4WD switch.
J8W-40 INSTRUMENT CLUSTERÐYJ VEHICLES 8W - 40 - 1

MALFUNCTION INDICATOR (CHECK ENGINE)
LAMP
The Powertrain Control Module (PCM) provides
ground for the malfunction indicator (Check Engine)
lamp on circuit G3. Circuit G3 connects to cavity 32
of the PCM. Circuit G5 connects to the instrument
cluster and supplies battery voltage for the malfunc-
tion indicator lamp. When illuminated, the malfunc-
tion indicator lamp displays the message CHECK
ENGINE.
For information regarding diagnostic trouble code
access using the malfunction indicator lamp, refer to
Group 14, Fuel Systems.
UP-SHIFT LAMP
On vehicles equipped with a manual transmission,
the Powertrain Control Module (PCM) provides
ground for the Up-Shift lamp on circuit K54. Circuit
G5 provides battery voltage for the lamp.
ABS WARNING LAMP
Circuit G5 provides power for the ABS warning
lamp at the instrument cluster. Ground for the ABS
warning lamp is provided by either the ABS control
module or by the ABS power relay when the relay is
not energized. The ABS control module illuminates
the lamp by providing ground on circuit G19.
Circuit G19 splices to connect to circuit B15
through a diode. When the ABS power relay is not
energized, it connects circuit B15 to circuit Z12. The
ground path for the warning lamp is provided
through the diode to circuit B15, through the ABS
power relay to ground on circuit Z12.
The diode between circuit G19 and B15 prevents
voltage from flowing to the ABS control module when
the ABS power relay switches to supply power on cir-
cuit B15.
BRAKE WARNING LAMP
Circuit G5 provides battery voltage for the brake
warning lamp. Circuit G11 can provide ground for
the lamp in 3 ways. The first ground path is through
the ignition switch when the key is in the START po-
sition.
The second ground path for the brake warning
lamp on circuit G11 is through the case grounded
brake warning switch. When the switch closes it pro-
vides a ground.
The third ground path on circuit G11 is through
the case grounded park brake switch. When the
switch closes it provides ground.
HIGH BEAM INDICATOR LAMP
Circuit G34 supplies power for the high-beam indi-
cator lamp when the operator either flashes the opti-
cal horn (high beams) or selects high beam operation.
Circuit Z1 provides the ground path for the lamp.
Circuit L3 from the headlamp switch powers the
high beam circuits of the headlamps. On vehicles not
equipped with Daytime Running Lamps (DRL), cir-
cuit G34 double crimps to circuit L3 at the bulkhead
connector.
On vehicles equipped with DRL, circuit L3 splices
to the DRL module. The DRL module powers circuit
G34.
TURN SIGNAL INDICATOR LAMPS
Circuit L61 supplies battery voltage to the left turn
signal indicator lamp. The right turn signal indicator
lamp receives battery voltage from circuit L60. The
turn signal/hazard flasher switch powers circuits L60
and L61. Circuit Z1 provides ground for the lamps.
HELPFUL INFORMATION
²If the warning lamps, gauges and indicator lamps
don't operate, check fuse 4 in the PDC and fuse 9 in
the fuse block.
²If the illumination lamps don't operate, check fuse
10 in the fuse block.
DIAGRAM INDEX
Component Page
4WD Switch............................8W-40-9
ABS Control Module......................8W-40-5
Brake Warning Switch.....................8W-40-5
Combination Buzzer.....................8W-40-7, 8
Daytime Running Lamp (DRL) Module.........8W-40-4, 6
Engine Coolant Temperature Sensor...........8W-40-7, 8
Engine Oil Pressure Sensor..................8W-40-9
Fuse 3 (PDC).......................8W-40-3, 7, 8
Fuse 4 (PDC).......................8W-40-4, 7, 8
Fuse 7 (PDC)...........................8W-40-6
Fuse 8 (Fuse Block)...................8W-40-3, 7, 8
Fuse 9 (Fuse Block).......................8W-40-8
Fuse 10 (Fuse Block).................8W-40-3, 7, 10
Gauge Package......................8W-40-7, 8, 9
Headlamp Switch...................8W-40-3, 6, 7, 8
Headlamp Dimmer Switch...................8W-40-6
Ignition Switch......................8W-40-4, 5, 8
Instrument Cluster...................8W-40-3 thru 9
Panel Lamp Dimmer Switch..............8W-40-3, 7, 8
Park Brake Switch........................8W-40-5
Powertrain Control Module.................8W-40-4, 5
8W - 40 - 2 8W-40 INSTRUMENT CLUSTERÐYJ VEHICLESJ

HORN/CIGAR LIGHTER
HORN
The horn system uses a switch and horn relay. The
horn switch is in the center of the steering wheel.
Circuit A4 from fuse 8 in the Power Distribution
Center (PDC) feeds circuit F31 through fuse 15 in
the PDC. Circuit F31 is HOT at all times and powers
the coil and contact sides of the horn relay.
When the case grounded horn switch is pressed,
circuit X3 provides ground for the coil side of the re-
lay and the contacts close. When the contacts close,
circuit X2 supplies voltage to the horn. Circuit Z1
provides ground for the horn.
HELPFUL INFORMATION
²The horn switch is grounded to the steering wheel.
²Circuit F31 is double crimped at the coil side of
the horn relay.
²Check fuse 8 in the PDC and fuse 15 in the fuse
block.
CIGAR LIGHTER
In the ACCESSORY or RUN position, the ignition
switch supplies voltage to fuse 7 in the fuse block on
circuit A31. Fuse 7 feeds circuit F30 which connects
to the cigar lighter. When the lighter is depressed,
the contacts inside of the lighter element close and
voltage flows to ground on circuit Z1.
HELPFUL INFORMATION
²In the ACCESSORY or RUN position, the ignition
switch connects circuit A1 from fuse 4 in the PDC
with circuit A31.
²Circuit F30 also powers the radio and radio relay.
DIAGRAM INDEX
Component Page
Cigar Lighter...........................8W-41-3
Fuse 4 (PDC)...........................8W-41-3
Fuse 8 (PDC)...........................8W-41-2
Fuse 11 (PDC)..........................8W-41-2
Fuse 7 (Fuse Block).......................8W-41-3
Horn.................................8W-41-2
Horn Relay.............................8W-41-2
Horn Switch............................8W-41-2
Ignition Switch..........................8W-41-3
J8W-41 HORN/CIGAR LIGHTERÐYJ VEHICLES 8W - 41 - 1

AIR CONDITIONING AND HEATER
GENERAL INFORMATION
On vehicles built with the 2.5L engine, the electri-
cal system has provisions for dealer installed air con-
ditioning. The provisions consist of two connectors
which include circuitry for:
²Circuit C1 - Ignition feed
²Circuit C21 - Blower motor switch
²Circuit C91 - A/C request signal
²Circuit C20 - A/C select signal
²Circuit C13 - Ground for coil side of A/C compres-
sor clutch relay
²Circuit G5 - Battery voltage for coil side of A/C
compressor clutch relay
A/C COMPRESSOR
When the ignition switch is in the RUN position it
connects circuit A1 from fuse 4 in the Power Distri-
bution Center (PDC) to circuit A22. Circuit A22 sup-
plies battery voltage to fuse 12 in the fuse block.
Fuse 12 powers circuit C1.
Circuit C1 supplies battery voltage to the A/C
blower switch. Circuit C21 connects the A/C blower
switch to the A/C low pressure switch.
When the operator selects A/C operation, the A/C
blower switch provides the A/C request signal to cav-
ity 27 of the Powertrain Control Module (PCM) on
circuit C91. At the same time, the blower switch sup-
plies voltage through the A/C thermostat to circuit
C21.
Circuit C21 supplies voltage to the A/C low pres-
sure switch. When the A/C low pressure switch
closes, circuit C20 provides battery voltage to the
contact side of the A/C compressor clutch relay and
provides the A/C select signal to the PCM. Circuit
C20 is double crimped at the contact side of the re-
lay. The C20 circuit branch from the relay supplies
the A/C select input to cavity 28 of the PCM.
After receiving the A/C request signal, the PCM en-
ergizes the A/C compressor clutch relay by providing
ground for the coil side of the relay on circuit C13.
Circuit C13 connects to cavity 34 of the PCM.
Circuit G5 from fuse 9 in the fuse block supplies
voltage to the coil side of the relay. In the START or
RUN positions the ignition switch connects circuit A1
from fuse 4 in the PDC with circuit A21. Circuit A21
connects to the fuse block bus bar that powers circuit
C5 through fuse 9.
When the PCM energizes the A/C compressor
clutch relay, the relay switches from its normally
grounded position to connect circuit C20 to circuit
C3. Circuit C3 supplies voltage to the case grounded
A/C compressor clutch.
HELPFUL INFORMATION
²Circuit G5 is double crimped at the coil side of the
A/C compressor clutch relay. The G5 branch from the
relay continues to the back-up lamp switch.
²Circuit Z1 provides ground for the A/C compressor
clutch relay when the relay is in its normally
grounded position.
A/C-HEATER BLOWER MOTOR
When the ignition switch is in the RUN position it
connects circuit A1 from fuse 4 in the Power Distri-
bution Center (PDC) to circuit A22. Circuit A22 sup-
plies battery voltage to fuse 12 in the fuse block.
Fuse 12 powers circuit C1.
Circuit C1 supplies battery voltage to the A/C
blower switch. In the LOW position, the A/C blower
switch supplies voltage to the low speed brush of the
blower motor. In the MEDIUM position, the switch
supplies voltage to the medium speed bush of the
blower motor. In the HIGH position, the switch sup-
plies voltage to the high speed brush of the blower
motor.
The blower motor has a field jumper. The ground
circuit for the blower motor connects to the cigar
lighter. Circuit Z1 provides ground for the blower mo-
tor and the cigar lighter.
HELPFUL INFORMATION
²Check fuse 4 in the PDC.
²Check fuse 12 in the fuse block.
DIAGRAM INDEX
Component Page
A/C Compressor Clutch.....................8W-42-4
A/C Compressor Clutch Relay................8W-42-4
A/C Thermostat..........................8W-42-5
Blower Motor...........................8W-42-5
Blower Motor Switch......................8W-42-5
Fuse 4 (PDC).........................8W-42-4, 6
Fuse 7 (Fuse Block).......................8W-42-6
Fuse 9 (Fuse Block).....................8W-42-4, 6
Fuse 12 (Fuse Block)....................8W-42-4, 6
Ignition Switch........................8W-42-4, 6
Powertrain Control Module.................8W-42-4, 6
8W - 42 - 2 8W-42 AIR CONDITIONING/HEATERÐYJ VEHICLESJ

INTERIOR LIGHTING
INDEX
page page
Accessory Lamp and Heater Control Panel Lamp . . 1
Combination Buzzer........................ 1
Courtesy Lamps and Dome Lamps............. 1
Diagram Index............................ 2General Information........................ 1
Transmission Range Lamp................... 1
Underhood Lamp.......................... 1
GENERAL INFORMATION
Circuit M1 supplies power to the underhood lamp,
dome lamp, right courtesy lamp and left courtesy
lamp. Fuse 12 in the Power Distribution Center
(PDC) protects circuit M1. Circuit A4 from fuse 8 in
the PDC supplies voltage to fuse 12 and circuit M1.
Fuse 12 is referred to as the Ignition Off Draw (IOD)
fuse.
COURTESY LAMPS AND DOME LAMPS
Circuit M1 supplies battery voltage to the dome
lamps and the right and left courtesy lamps. Circuit
M2 provides ground for the lamps through either the
case grounded door jamb switches or through the
dimmer switch to circuit Z1.
In the ON position, the dimmer switch connects
circuit M2 to ground on circuit Z1. When a door
opens, the case grounded door jamb switch closes and
provides ground for the lamps on circuit M2.
HELPFUL INFORMATION
²Circuit M1 also supplies voltage for radio memory,
underhood lamp and the ABS data link connector.
UNDERHOOD LAMP
Circuit M1 supplies battery voltage for the under-
hood lamp. A mercury switch in series after the lamp
connects the lamp to ground on circuit Z1. When the
hood is raised, mercury inside the switch moves to a
position where it connects circuit M1 to circuit Z1, il-
luminating the lamp. The underhood lamp is wired
in parallel with other components on circuit M1.
ACCESSORY LAMP AND HEATER CONTROL PANEL
LAMP
Circuit E1 from the dimmer switch supplies bat-
tery voltage to fuse 10 in the fuse block when the
dimmer switch is in the LOW or ON position. Fuse
10 protects circuit E2 which supplies power to the
heater control panel lamp and the accessory lamp.
Circuit Z1 provides ground for each lamp.
TRANSMISSION RANGE LAMP
Circuit E1 from the dimmer switch supplies bat-
tery voltage to fuse 10 in the fuse block when thedimmer switch is in the LOW or ON positions. Fuse
10 protects circuit E2 which supplies power to the
transmission range lamp. The lamp is case grounded.
COMBINATION BUZZER
The combination buzzer module sounds an audible
warning tone. The tone sounds for seat belt warning
and when the key is in the ignition switch while the
drivers door is open. The tone also sounds when the
ignition switch is in the ON position while the driv-
ers side seat belt is not buckled. Refer to Group 8U
for buzzer operation.
Fuses 3 and 9 in the fuse block protect the combi-
nation buzzer. Fuse 3 powers circuit F32 which con-
nects to the buzzer. Circuit A6 from fuse 3 in the
Power Distribution Center (PDC) supplies power to
the fuse block for circuit F32.
Circuit G5 from fuse 9 also provides voltage to the
combination buzzer when the ignition switch is in
the START or RUN position. The ignition switch con-
nects circuit A1 from fuse 4 in the PDC to circuit
A21. Circuit A21 connects to the fuse block.
When the key-in switch closes, it connects circuit
G26 to circuit G16. Circuit G16 connects to the driv-
ers side door jamb switch. When the drivers side door
is open and the key-in switch is closed, the case
grounded door jamb switch closes and supplies
ground for the buzzer. Circuit G26 from the combina-
tion buzzer connects to the key-in switch.
Circuit G13 form the buzzer powers the seat belt
warning lamp in the instrument cluster. Circuit Z1
at the instrument cluster provides ground for the
lamp.
Circuit G10 from the buzzer connects to the seat
belt switch. When the seat belt is unlatched, the seat
belt switch closes providing ground on circuit Z1.
Circuit Z1 also grounds the combination buzzer
module.
HELPFUL INFORMATION
²Circuit F32 also powers the stop lamp switch.
²Circuit G5 also provides power for the instrument
cluster gauges and warning lamps, heated rear win-
dow relay and A/C compressor clutch relay. On Cana-
J8W-44 INTERIOR LIGHTINGÐYJ VEHICLES 8W - 44 - 1

RADIO
RADIO MEMORY
Circuit M1 from the Ignition Off Draw (IOD) fuse
in the Power Distribution Center (PDC) supplies
power for the radio memory. The IOD fuse is re-
moved during vehicle shipping to prevent excessive
battery draw.
Circuit A4 from fuse 8 in the PDC supplies voltage
to the IOD fuse in cavity 12. Circuit A4 is HOT at all
times.
RADIO ILLUMINATION
Circuit E2 supplies battery voltage to the radio il-
lumination lamps when the headlamps or parking
lamps are ON and the dimmer switch is in the LOW
or ON positions.
Circuit E22 supplies battery voltage for the radio
clock and station frequency display. Circuit E22 orig-
inates at the radio illumination relay and is fed by
either circuit F30 or circuit E2 depending on the
switch position inside the relay.
When the headlamps and parking lamps are OFF,
the radio illumination relay is in its normal At-Rest
position. In the At Rest position, the relay connects
circuit F30 from fuse 7 in the fuse block to circuit
E22.
When the headlamps or parking lamps are ON, cir-
cuit L7 from the headlamp switch supplies battery
voltage to the coil side of the radio illumination relay.
Circuit Z1 provides ground for the coil side of the re-
lay.
When voltage is present on circuit L7, the radio il-
lumination relay switches from its at rest position to
connect circuit E2 to circuit E22.
HELPFUL INFORMATION
²Circuit A31 supplies voltage to the fuse block for
circuit F30 when the ignition switch is in the AC-
CESSORY or RUN positions. In these positions the
ignition switch connects circuit A1 from fuse 4 in the
PDC to circuit A31. Circuit A31 powers a bus bar in
the fuse block that feeds circuit F30 through fuse 7.
²Circuit A6 from fuse 3 in the PDC supplies power
to the fuse block for fuse 8. Fuse 8 protects circuit
F33. When the headlamps or parking lamps are ON,the headlamp switch connects circuit F33 to circuit
L7. When the adjustable dimmer switch is in the
LOW to ON positions, it connects circuit L7 to circuit
E1. Circuit E1 powers fuse 10 in the fuse block. Fuse
10 in the fuse block protects circuit E2.
SPEAKERS
Circuit X53 feeds the speaker on the left side of the
instrument panel. Circuit X55 is the return from the
speaker to the radio.
Circuit X54 feeds the right instrument panel
speaker. Circuit X56 is the return from the speaker
to the radio.
The speaker feed and return circuits are double
crimped at the front speakers and continue to the
connector for the rear speakers. If the vehicle is not
equipped with the rear speaker sound bar, a jumper
is installed in the harness to simulate rear speaker
load.
Circuit X51 feeds the left rear speaker. Circuit X57
is the return from the speaker to the radio.
Circuit X52 feeds the right rear speaker. Circuit
X58 is the return from the speaker to the radio.
DIAGRAM INDEX
Component Page
Fuse 3 (PDC)...........................8W-47-3
Fuse 4 (PDC)...........................8W-47-2
Fuse 7 (Fuse Block).......................8W-47-2
Fuse 8 (Fuse Block).......................8W-47-3
Fuse 8 (PDC)...........................8W-47-2
Fuse 10 (Fuse Block)......................8W-47-3
Fuse 12 (PDC)..........................8W-47-2
Headlamp Switch.........................8W-47-3
Ignition Switch..........................8W-47-2
Left Front Speaker........................8W-47-4
Left Rear Speaker........................8W-47-5
Panel Lamp Dimmer Switch..................8W-47-3
Radio............................8W-47-2, 3, 4
Radio Illumination Relay....................8W-47-2
Right Front Speaker.......................8W-47-4
Right Rear Speaker.......................8W-47-5
J8W-47 AUDIO SYSTEMÐYJ VEHICLES 8W - 47 - 1

HEATED REAR WINDOW
HEATED REAR WINDOW
The heated rear window relay supplies power to
heated rear window grid. When the operator presses
the heated rear window switch, the contacts inside
the switch momentarily close and circuit C16 con-
nects the relay timer to ground on circuit Z1. This
causes the relay to change state and complete a cir-
cuit to energize the coil side of the relay and start
the relay timer. Circuit G5 from fuse 9 in the fuse
block supplies voltage to the coil side of the relay.
Circuit Z1 provides ground for the relay.
When the heated rear window relay energizes, the
contacts inside the relay close and connect circuit
F32 to circuit C15. Fuse 3 in the fuse block protects
circuit F32.
Circuit C15 is double crimped at the heated rear
window relay. One branch of circuit C15 powers the
indicator lamp in the heated rear window switch.
The other branch of circuit C15 powers the heated
rear window grid. Circuit Z1 provides ground for the
heated rear window grid.
At the rear window grid, circuits C15 and Z1 pass
through lift gate support struts.
HELPFUL INFORMATION
²When the ignition switch is in the START or RUN
positions, it connects circuit A1 from fuse 4 in the
Power Distribution Center (PDC) to circuit A21. Cir-
cuit A21 supplies battery voltage to the fuse block
bus bar that powers circuit G5 through the fuse in
cavity 9.
²Circuit A6 from PDC fuse 3 supplies battery volt-
age to the fuse block bus bar that feeds fuse 3 and
circuit F32. Check fuse 3 in the PDC and fuse 3 in
the fuse block.
²Check for broken grid lines on the window.
²Check for a broken bus bar or disconnected leads
at the rear window.
²Check for a good ground.
DIAGRAM INDEX
Component Page
Fuse 3 (PDC)...........................8W-48-2
Fuse 4 (PDC)...........................8W-48-2
Fuse 6 (Fuse Block).......................8W-48-2
Fuse 9 (Fuse Block).......................8W-48-2
Heated Rear Window Relay..................8W-48-2
Heated Rear Window Grid...................8W-48-3
Heated Rear Window Switch.................8W-48-3
J8W-48 HEATED REAR WINDOWÐYJ VEHICLES 8W - 48 - 1

FRONT LIGHTING
INDEX
page page
Daytime Running Lamp (DRL) ModuleÐCanadian
Vehicles Only........................... 2
Diagram Index............................ 2
Fog Lamps............................... 1Headlamps............................... 1
Parking Lamps............................ 1
HEADLAMPS
The headlamp switch has three positions: ON,
PARK (parking lamps) and OFF. Two circuits, L2 and
L20, connect the headlamp switch to the headlamp
dimmer/optical horn switch. The dimmer switch feeds
the low and high beams of the headlamps.
HEADLAMP SWITCH IN OFF OR PARKING
LAMP POSITION
Circuit A3 from fuse 7 in the Power Distribution
Center (PDC) supplies battery voltage to the head-
lamp switch. The headlamp switch has an internal
circuit breaker that connects circuit A3 to circuit
L20. The switch connects circuit A3 to circuit L2
when the headlamps are ON.
Circuit L20 connects to the dimmer switch. Circuit
L20 powers the high beams of the head lamps on cir-
cuit L3 when the operator flashes the headlamps
with the turn signal stalk.
HEADLAMP SWITCH IN ON POSITION
When the headlamp switch is in the ON position,
the A3 circuit from the PDC connects to circuit L2.
Circuit L2 connects to circuit L4 through the dimmer
switch. Circuit L4 powers the low beam of the head-
lamps.
When the operator selects high beam operation
with the turn signal stalk, the dimmer switch con-
nects circuit L20 to circuit L3. Circuit L3 supplies
battery voltage to the high beams.
HEADLAMP GROUND
Although circuit Z1 provides ground for both the
right and left headlamps, it has different termination
points for each. For the right headlamp, the Z1 cir-
cuit terminates at the radiator right support. For the
left headlamp, the Z1 circuit terminates at the left
radiator support.
HELPFUL INFORMATION
²Check fuse 7 in the PDC.
²The headlamp switch has an internal circuit
breaker.
²For the left front parking lamp, turn signal, side
marker lamp, headlamp, and fog lamp, circuit Z1 ter-
minates at the left radiator support.²For the right front parking lamp, turn signal, side
marker lamp, headlamp, and fog lamp, circuit Z1 ter-
minates at the right radiator support.
PARKING LAMPS
Circuit A6 from fuse 3 in the Power Distribution
Center (PDC) connects to the fuse block bus bar that
powers circuit F33. Fuse 8 in the fuse block protects
circuit F33. Circuit F33 connects to the headlamp
switch.
The headlamp switch has three positions: ON,
PARK (parking lamps) and OFF, plus a dimmer
switch. When the headlamp switch is in the PARK or
ON position, the switch connects circuit F33 to cir-
cuit L7. From the headlamp switch, circuit L7
branches to power the front parking lamps, rear tail
lamps, and side marker lamps. Circuit L7 also pow-
ers the park lamp relay, if equipped with fog lamps.
GROUND CIRCUIT
²For the left front parking lamp, turn signal, side
marker lamp, headlamp, and fog lamp, circuit Z1 ter-
minates at the left radiator support.
²For the right front parking lamp, turn signal, side
marker lamp, headlamp, and fog lamp, circuit Z1 ter-
minates at the right radiator support.
HELPFUL INFORMATION
²Check fuse 3 in the PDC.
²Check fuse 8 in the fuse block.
²Circuit L7 also feeds the radio, if equipped.
FOG LAMPS
The fog lamps are controlled by the fog lamp
switch and two relays. The fog lamps operate only
when the headlamp switch is in the ON position, and
the operator has selected low-beam operation. When
the headlamps are in high-beam operation, the fog
lamps will not operate.
When the headlamps or parking lamps are ON, cir-
cuit L7 from the headlamp switch supplies battery
voltage to the coil side of the park lamp relay. When
the operator presses the fog lamp switch, it provides
ground for the coil side of the park lamp relay. This
energizes the relay.
J8W-50 FRONT LIGHTINGÐYJ VEHICLES 8W - 50 - 1

When the park lamp relay energizes, the relay con-
tacts close and connect circuit F81 from fuse 6 in the
fuse block to circuit L36. Circuit L36 connects to the
contact side of the high beam relay. The contacts in
the high beam relay are normally closed. Battery
voltage flows through high beam relay to the fog
lamps on circuit L39. Circuit L39 also splices to the
lamp in the fog lamp switch.
Circuit L3 from the dimmer switch provides power
for the high beams of the headlamps and connects to
Circuit G34. Circuit G34 powers the coil side of the
high beam relay. Circuit Z1 provides ground for the
coil. When the operator selects high beam operation
or flashes the optical horn, circuit G34 energizes the
high beam relay. When energized, the normally
closed contacts in the relay open, shutting off battery
voltage to the fog lamps on circuit L39.
HELPFUL INFORMATION
²Circuit A6 from fuse 3 in the PDC supplies voltage
to the fuse block for fuses in cavities 3 and 6. Fuse 6
in the fuse block protects circuit F81 which powers
the contact side of the park lamp relay.
²In the high beam position, the dimmer switch con-
nects circuit L20 from the headlamp switch to circuit
L3. The headlamp switch connects circuit A3 from
fuse 7 in the PDC with circuit L20. Circuits A3 and
L20 are HOT at all times.
DAYTIME RUNNING LAMP (DRL) MODULEÐ
CANADIAN VEHICLES ONLY
On Canadian vehicles, the low-beam headlamps op-
erate when the ignition switch is in the RUN position
and the headlamp switch is OFF.
When the ignition switch is in the START or RUN
positions, circuit A1 from fuse 4 in the Power Distri-
bution Center (PDC) connects to circuit A21. Circuit
A21 supplies voltage to circuit G5 through fuse 9 in
the fuse block. Circuit G5 splices to supply battery
voltage to the DRL module.
Circuit L20 from the headlamp switch connects to
the DRL module. Circuit L20 is HOT at all times.
The DRL module receives the vehicle speed sensor
input from circuit G7. Circuit G34 from the DRLmodule provides power for the high beam indicator
lamp in the instrument cluster.
Circuit L4 feeds the low beams of the headlamps.
When the headlamp switch is in the OFF position,
the DRL module powers the left and right headlamps
on circuit L4. When the headlamps are ON, the dim-
mer switch powers the low beams on circuit L4.
Circuit L3 feeds the high beams of the headlamps.
When the operator flashes the high beams with the
turn signal stalk, the DRL senses voltage on circuit
L3. When it senses voltage on circuit L3, the DRL
module stops supplying power to the low beams on
circuit L4.
Circuit Z1 provides ground for the DRL module.
Circuit Z1 terminates at the radiator left side sup-
port.
DIAGRAM INDEX
Component Page
Daytime Running Lamp (DRL) Module. . . .8W-50-3, 7, 9, 11
Fog Lamps.............................8W-50-9
Fog Lamp Switch........................8W-50-9
Fuse 3 (PDC)...........................8W-50-3
Fuse 4 (PDC)..........................8W-50-10
Fuse 6 (Fuse Block).......................8W-50-8
Fuse 7 (PDC)........................8W-50-3, 10
Fuse 8 (Fuse Block).......................8W-50-3
Fuse 9 (Fuse Block)......................8W-50-10
Headlamp Switch....................8W-50-3, 8, 10
Headlamp Dimmer Switch.................8W-50-3, 8
High Beam Relay.........................8W-50-9
Ignition Switch.........................8W-50-10
Instrument Cluster..................8W-50-3 thru 10
Left Headlamp.........................8W-50-4, 6
Left Park, Turn Signal Lamp...............8W-50-4, 6
Left Side Marker Lamp...................8W-50-4, 6
Park Lamp Relay.........................8W-50-8
Powertrain Control Module..................8W-50-11
Right Headlamp........................8W-50-5, 7
Right Park, Turn Signal Lamp..............8W-50-5, 7
Right Side Marker Lamp..................8W-50-5, 7
8W - 50 - 2 8W-50 FRONT LIGHTINGÐYJ VEHICLESJ

REAR LIGHTING
TAIL LAMPS AND LICENSE PLATE LAMPS
Circuit A6 in the Power Distribution Center (PDC)
connects to a bus bar in the fuse block. The fuse
block bus bar powers circuit F33. Circuit F33 con-
nects to the headlamp switch. Fuse 3 in the PDC
protects circuit A3. Fuse 8 in the fuse block protects
circuit F33.
The headlamp switch has three positions: ON,
PARK (parking lamps) and OFF, plus a dimmer
switch. When the headlamp switch is in the PARK or
ON position, the switch connects circuit F33 to cir-
cuit L7. From the headlamp switch, circuit L7
branches to power the front parking lamps and rear
tail and license plate lamps. The lamps are case
grounded.
HELPFUL INFORMATION
²If the vehicle is equipped with factory installed fog
lamps, circuit L7 splices to feed the park lamp relay.
²Jumper harnesses connect the tail, stop, turn sig-
nal lamp to the body harness.
²Check fuse 3 in the PDC.
²Check fuse 8 in the fuse block.
²Circuit L7 also feeds the radio, if equipped.
STOP LAMPS AND CHMSL LAMPS
Circuit A6 from fuse 3 in the Power Distribution
Center (PDC) supplies voltage to the fuse block bus
bar. The bus bar powers circuit F32 through fuse 3 in
the fuse block. Circuit F32 connects to the stop lamp
switch.
When the operator depresses the brake pedal, the
stop lamp switch closes, and connects circuit F32 to
circuit L50. Circuit L50 connects to the CHMSL
lamps and turn signal/hazard flasher. Circuit Z1 pro-
vides ground for the CHMSL lamps. The turn signal/
hazard flasher supplies current to the L62 and L63
circuits. Circuit L62 powers the right stop lamp. Cir-
cuit L63 powers the left stop lamp. The stop lamps
are case grounded.
HELPFUL INFORMATION
²Circuits L50 and Z1 pass through contacts in the
rear door before reaching the CHMSL lamps.
²Check fuse 3 in the PDC.²Check fuse 3 in the fuse block.
²Check for continuity across the stop lamp switch
when it is closed.
²If the vehicle is equipped with anti-lock brakes,
circuit L50 connects to the ABS module.
BACK-UP LAMPS
In the START or RUN position, the ignition switch
connects circuit A1 from fuse 4 in the Power Distri-
bution Center (PDC) to circuit A21. Circuit A21 feeds
a bus bar in the fuse block that powers circuit G5
through fuse 9.
Circuit G5 splices to supply power to the back-up
lamp switch. On automatic transmission vehicles, the
back-up lamp switch is part of an assembly that in-
cludes the PARK/NEUTRAL position switch.
When the operator puts the transmission in Re-
verse, the back-up lamp switch connects circuit G5 to
circuit L1. Circuit L1 feeds the case grounded
back-up lamps.
HELPFUL INFORMATION
²Check fuse 4 in the PDC.
²Check fuse 9 in the fuse block.
²Check for continuity across the back-up lamp
switch when it is closed.
DIAGRAM INDEX
Component Page
ABS Control Module......................8W-51-3
Back-Up Lamps..........................8W-51-4
Back-Up Lamp Switch.....................8W-51-2
Center High Mounted Stop Lamps (CHMSL).......8W-51-3
Fuse 3 (Fuse Block).......................8W-51-2
Fuse 3 (PDC)...........................8W-51-2
Fuse 4 (PDC)...........................8W-51-2
Fuse 9 (Fuse Block).......................8W-51-2
Fuse 8 (Fuse Block).......................8W-51-2
Headlamp Switch.........................8W-51-2
Ignition Switch..........................8W-51-2
Powertrain Control Module..................8W-51-3
Stop Lamp Switch........................8W-51-3
Tail, Stop, and Turn Signal Lamps.............8W-51-4
J8W-51 REAR LIGHTINGÐYJ VEHICLES 8W - 51 - 1