fuses JEEP CHEROKEE 1995 Service User Guide
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Page 601 of 2198

ABS pump motor relay. The ABS control module pro-
vides ground for the relay on circuit B116. Circuit
B116 connects to cavity 15 of the ABS control mod-
ule.
When the ABS pump motor energizes, it connects
circuit A10 from PDC fuse 8 to circuit B233. Circuit
B233 supplies battery voltage to the pump motor.
Circuit Z12 provides ground for the pump motor.
PUMP MOTOR SPEED SENSOR
The input from the pump motor speed sensor tells
the ABS control module that the pump is operating.
Circuits B219 and B220 from the control module con-
nect to the speed sensor.
BRAKE SWITCH INPUT
Circuit L50 from the stop lamp provides the brake
switch input to the ABS control module. When the
brake pedal is depressed, the stop lamp switch closes
to supply battery voltage from circuit L9 to circuit
L50. Circuit L50 connects to cavity 32 of the ABS
control module. Circuit L9 originates at fuse 4 in the
Power Distribution Center (PDC).
HYDRAULIC CONTROL UNIT
When the ABS power relay energizes, two branches
of circuit B235 splice to supply voltage to the isola-
tion and dump solenoids in the hydraulic control
unit. The hydraulic control unit contains three sepa-
rate isolation solenoids and three separate dump so-
lenoids. The ABS control module activates the decay
and isolation solenoids by providing separate ground
paths for each.
The ABS module provides a ground path for the
rear isolation solenoid on circuit B251. Circuit B251
connects to cavity 54 of the ABS control module.
For the right front isolation solenoid, the ABS mod-
ule provides a ground path on circuit B249. Circuit
B249 connects to cavity 38 of the ABS control mod-
ule.
On circuit B245, the ABS module provides ground
for the left front isolation solenoid. Circuit B245 con-
nects to cavity 20 of the ABS control module.
The ABS module provides a ground path for the
rear decay solenoid on circuit B254. Circuit B254
connects to cavity 36 of the ABS control module.For the right front decay solenoid, the ABS module
provides a ground path on circuit B248. Circuit B248
connects to cavity 21 of the ABS control module.
On circuit B243, the ABS module provides ground
for the left decay solenoid. Circuit B243 connects to
cavity 2 of the ABS control module.
ABS WARNING LAMP
Circuit F87 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 B205.
Circuit B205 splices to connect to circuit B235
through a diode. When the ABS power relay is not
energized, it connects circuit B235 to circuit Z12. The
ground path for the warning lamp is through the di-
ode to circuit B235, through the ABS power relay to
ground on circuit Z12.
The diode between circuit B205 and B235 prevents
voltage from flowing to the ABS control module when
the ABS power relay switches to supply power on cir-
cuit B235.
DATA LINK CONNECTOR
Circuit D1 from cavity 23 of the ABS control mod-
ule receives data from the DRB scan tool through the
data link connector. The ABS control module trans-
mits data to the scan tool through the connector on
circuit D2. Circuit D2 originates at cavity 42 of the
ABS control module.
Through the data link connector, circuit Z12 pro-
vides ground for the DRB scan tool.
Circuit A4 from fuse 10 in the Power Distribution
Center (PDC) supplies power to fuse 5 in the PDC.
Fuse 5 powers circuit F39 which supplies battery
voltage to the scan tool through the diagnostic con-
nector.
HELPFUL INFORMATION
²Check fuses 10 and 5 in the PDC.
²If the vehicle is equipped with an automatic trans-
mission, circuits D1 and D2 are double crimped at
the data link connector and connect to the Power-
train Control Module (PCM).
8W - 32 - 2 8W-32 ANTI-LOCK BRAKESÐXJ VEHICLESJ
Page 626 of 2198

AIR CONDITIONING/HEATER
CONTENTS
page page
A/C-HEATER SYSTEM...................... 1 HEATERSYSTEM......................... 1
GENERAL INFORMATION
This section of the wiring diagrams is divided into
two sub-sections; Heater, and A/C and Heater. When
referring to the circuit descriptions or wiring dia-
grams, ensure that you use the correct sub-section.
HEATER SYSTEM
BLOWER MOTOR
In the RUN or ACCESSORY position, the ignition
switch connects circuit A1 from fuse 6 in the Power
Distribution Center (PDC) to circuit A48. Circuit A48
supplies battery voltage to fuse 5 in the fuse block.
Fuse 5 supplies power to the heat mode switch on
circuit C7.
Circuit C43 from the heat mode switch splices to
supply voltage to the blower motor switch and the
blower motor resistor block. The blower motor switch
sets blower motor speed to HIGH, M1, M2, or LOW.
When the blower motor switch is in the LOW posi-
tion, circuit C43 from the heat mode supplies voltage
to the resistor block. Voltage does not pass through
the blower motor switch in the LOW position.In the M1 position, the blower motor switch sup-
plies voltage to the resistor block on circuit C4. From
circuit C4, voltage passes through three resistors in
the resistor block to the blower motor on circuit C1.
In the M2 position, the blower motor supplies volt-
age to the resistor block on circuit C6. From circuit
C6 voltage flows through two resistors to the blower
motor on circuit C1.
In the HIGH position, the blower motor switch con-
nects directly to the blower motor on circuit C1. Volt-
age does not pass through the resistor block.
Circuit Z1 provides ground for the blower motor.
A/C-HEATER SYSTEM
GENERAL INFORMATION
Several fuses supply power for the air conditioning/
heater system. In the START or RUN positions, the
ignition switch connects circuit A1 from fuse 6 in the
Power Distribution Center (PDC) to circuit A21. Cir-
cuit A21 powers a bus bar in the PDC that feeds cir-
cuit F12 through fuse 11. Circuit F12 feeds the
contact side of the A/C compressor clutch relay and
the coil side of the radiator fan relay (4.0L engine).
In the RUN or ACCESSORY position, the ignition
switch connects circuit A1 from fuse 11 in the PDC to
circuit A48. Circuit A48 supplies battery voltage to
fuse 5 in the fuse block. Fuse 5 supplies power to the
A/C-Heater control switch on circuit C7.
Fuse 13 in the PDC supplies battery voltage to the
contact side of the radiator fan relay on circuit F141.
Circuit A14 from fuse 15 in the PDC powers PDC
fuse 4.
BLOWER MOTOR
In the RUN or ACCESSORY position, the ignition
switch connects circuit A1 from fuse 6 in the PDC to
circuit A48. Circuit A48 supplies battery voltage to
fuse 5 in the fuse block. Fuse 5 supplies power to the
A/C-Heater control switch on circuit C7.
Circuit C43 from the A/C-heater switch splices to
supply voltage to the blower motor switch and the
blower motor resistor block. The blower motor switch
sets blower motor speed to HIGH, M1, M2, or LOW.
When the blower motor switch is in the LOW posi-
tion, circuit C43 from the A/C-Heater switch supplies
voltage to the resistor block. Voltage does not pass
through the blower motor switch in the LOW position
In the M1 position, the blower motor switch sup-
plies voltage to the resistor block on circuit C4. From
circuit C4, voltage passes through three resistors in
the resistor block to the blower motor on circuit C1.
J8W-42 AIR CONDITIONING/HEATERÐXJ VEHICLES 8W - 42 - 1
Page 670 of 2198

REAR LIGHTING
TAIL LAMPS AND REAR LICENSE PLATE LAMPS
Circuit A3 from fuse 5 in the Power Distribution
Center (PDC) connects to a bus bar in the fuse block
which feeds circuit L7. Fuse 15 in the fuse block pro-
tects circuit L7.
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 L7 to circuit
L90. From the headlamp switch, circuit L90 branches
to power the front parking lamps and rear tail
lamps, side marker lamps, and rear license plate
lamps.
GROUND CIRCUIT
Circuit Z1 provides a ground for the parking lamps,
tail lamps, and rear license plate lamps.
HELPFUL INFORMATION
²If the vehicle is equipped with factory installed
trailer tow, circuit L90 splices to the trailer tow har-
ness.
²Check fuse 5 in PDC.
²Check fuse 15 in the fuse block.
²When the headlamp switch is in the PARK or ON
position, circuit L7 also connects to circuit E2. Cir-
cuit E2 continues through fuse 19 in the fuse block.
Circuit E2 powers the illumination lamps.
STOP LAMPS AND CHMSL LAMPS
Circuit L9 from fuse 4 in the Power Distribution
Center (PDC) connects to the stop lamp switch.
When the operator depresses the brake pedal, the
stop lamp switch closes and connects circuit L9 to
circuit L50. Circuit L50 connects to the stop lamps
and Center High Mounted Stop Lamps (CHMSL).
Circuit Z1 provides a ground for the stop lamps and
CHMSL lamps.
HELPFUL INFORMATION
²Check fuse 4 in the PDC.
²Check for continuity across the stop lamp switch
when it is closed.
BACK-UP LAMPS
In the START or RUN position, the ignition switch
connects circuit A1 from fuse 6 in the Power Distri-
bution Center (PDC) to circuit A21. Circuit A21 feeds
a bus bar in the PDC that powers circuit F12
through fuse 11.
Circuit F20 supplies power to the back-up lamp
switch. On automatic transmission equipped vehicles,
the back-up lamp switch is part of an assembly that
includes the PARK/NEUTRAL position switch. When
the operator puts the transmission in REVERSE, the
back-up lamp switch connects circuit F20 to circuit
L10. Circuit L10 feeds the back-up lamps. Circuit Z1
provides ground for the back-up lamps.
HELPFUL INFORMATION
²Check fuses 6 and 11 in the PDC.
²Check for continuity across the back-up lamp
switch when it is closed.
DIAGRAM INDEX
Component Page
Back-Up Lamps........................8W-51-4, 5
Back-Up Lamp Switch.....................8W-51-2
Center High Mounted Stop Lamps (CHMSL).......8W-51-3
Fuse 15 (Fuse Block)......................8W-51-2
Fuse 4 (PDC)...........................8W-51-3
Fuse 6 (PDC)...........................8W-51-2
Fuse 7 (PDC)...........................8W-51-2
Fuse 11 (PDC)..........................8W-51-2
Headlamp Switch.........................8W-51-2
Ignition Switch..........................8W-51-2
License Plate Lamp.......................8W-51-3
Park/Neutral Position Switch.................8W-51-2
Side Marker Lamps.....................8W-51-4, 5
Stop Lamp Switch........................8W-51-3
Tail/Stop Lamps........................8W-51-4, 5
Turn Signal Lamps......................8W-51-4, 5
J8W-51 REAR LIGHTINGÐXJ VEHICLES 8W - 51 - 1
Page 700 of 2198

POWER MIRRORS
POWER MIRRORS
Four switches operates the left and right power
mirrors. One switch selects right or left mirror. Each
mirror has two motors; a LEFT/RIGHT motor and a
UP/DOWN motor. The motors switch polarity to al-
low mirror adjustment.
Circuit A7 from fuse 3 in the Power Distribution
Center (PDC) supplies battery voltage to fuse 16 in
the PDC. Fuse 16 in the PDC supplies voltage to the
Ignition Off Draw (IOD) fuse (fuse 9) in the fuse
block. Fuse 9 supplies power to circuit M1. Circuit
M1 connects to circuit P38. Circuit P38 powers the
power mirror switch. Circuit Z1 connects to the
power mirror switch and supplies ground for the
power mirror system.
RIGHT POWER MIRROR OPERATION
In the right position, the power mirror switch sup-
plies power to the right mirror LEFT/RIGHT motor
on circuit P79 when a rightward adjustment is made.
Circuit P77 provides the ground path the for right-
ward adjustments.
When the operator makes leftward adjustment, po-
larity reverses. For leftward adjustments, the switch
supplies battery voltage to the right mirror LEFT/
RIGHT motor on circuit P77. Circuit P79 supplies
ground for leftward adjustments.
During upward adjustments, the switch supplies
voltage to the right mirror UP/DOWN motor on cir-
cuit P79. Circuit P78 supplies ground during upward
adjustments.
For downward adjustments, the polarity is re-
versed, the switch powers the right mirror UP/
DOWN motor on circuit P78. Circuit P79 supplies the
ground path.
LEFT POWER MIRROR OPERATION
In the left position, the power mirror switch sup-
plies power to the left mirror LEFT/RIGHT motor on
circuit P79 when a rightward adjustment is made.
Circuit P81 provides the ground path the for right-
ward adjustments.
When the operator makes leftward adjustment, po-
larity reverses. For leftward adjustments, the switch
supplies battery voltage the left mirror LEFT/RIGHT
motor on circuit P81. Circuit P79 supplies ground for
leftward adjustments.
During upward adjustments, the switch supplies
voltage to the left mirror UP/DOWN motor on circuit
P79. Circuit P80 supplies ground during upward ad-
justments.
For downward adjustments, the polarity is re-
versed, the switch powers the left mirror UP/DOWN
motor on circuit P80. Circuit P79 supplies the ground
path.
HELPFUL INFORMATION
²Check fuse 9 in the fuse block
²Check fuses 3 and 16 in the PDC
DIAGRAM INDEX
Component Page
Fuse 3 (PDC)...........................8W-62-2
Fuse 9 (Fuse Block).......................8W-62-2
Fuse 16 (PDC)..........................8W-62-2
Power Mirrors..........................8W-62-2
Power Mirror Switch......................8W-62-2
J8W-62 POWER MIRRORSÐXJ VEHICLES 8W - 62 - 1
Page 872 of 2198

ANTI-LOCK BRAKES
INDEX
page page
ABS Power Relay.......................... 1
ABS Pump Motor Relay..................... 1
ABS Warning Lamp........................ 2
Acceleration Switch......................... 1
Brake Pedal Travel Sensor................... 2
Brake Switch Input......................... 2Data Link Connector........................ 2
Diagram Index............................ 3
General Information........................ 1
Hydraulic Control Unit....................... 2
Pump Motor Speed Sensor................... 2
Wheel Speed Sensors...................... 1
GENERAL INFORMATION
Three fuses supply power for the Anti-Lock Brake
System (ABS); fuses 6 and 10 in the Power Distribu-
tion Center (PDC) and fuse 2 in the fuse block. Fuses
6 and 10 in the PDC are connected directly to battery
voltage and are HOT all times. Fuse 2 in the fuse
block is HOT when the ignition switch is the RUN
Position.
In the RUN position, the ignition switch connects
circuit A1 from fuse 6 in the PDC with circuit A38.
Circuit A38 connects to a bus bar in the fuse block.
The bus bar feeds circuit B236 through fuse 2. Fuse
2 is a 2 amp fuse.
Circuit B236 connects to the coil side of the ABS
power relay and cavity 53 of the ABS control module.
Circuit Z1 provides ground for the ABS control
module. Circuit Z1 connects to cavities 1 and 19 of
the ABS control module.
Refer to group 5, Brakes for operational descrip-
tions of ABS system components.
WHEEL SPEED SENSORS
The all wheel anti-lock system uses four wheel
speed sensors; one for each wheel. Each sensor con-
verts wheel speed into an electrical signal that it
transmits to the ABS control module. A pair of
twisted wires connect to each sensor to provide sig-
nals to the ABS control module.
Circuits B6 and B7 provide signals to ABS control
module from the right front wheel speed sensor. Cir-
cuit B6 which provides the LOW signal connects to
cavity 29 of the ABS control module. Circuit B7 con-
nects to cavity 47 of the module and provides the
HIGH signal.
Circuits B8 and B9 provide signals to ABS control
module from the left front wheel speed sensor. Cir-
cuit B8, which provides the LOW signal, connects to
cavity 30 of the ABS control module. Circuit B9 con-
nects to cavity 48 of the module and provides the
HIGH signal.
Circuits B1 and B2 provide signals to ABS control
module from the right rear wheel speed sensor. Cir-
cuit B1 which provides the LOW signal connects tocavity 45 of the ABS control module. Circuit B2 con-
nects to cavity 27 of the module and provides the
HIGH signal.
Circuits B4 and B3 provide signals to ABS control
module from the left rear wheel speed sensor. Circuit
B3, which provides the LOW signal, connects to cav-
ity 28 of the ABS control module. Circuit B4 connects
to cavity 46 of the module and provides the HIGH
signal.
ACCELERATION SWITCH
During four-wheel drive operation, the acceleration
switch provides deceleration data to the ABS control
module. Refer to Group 5, Brakes for additional in-
formation.
Circuits B515, B516, and B517 connect the acceler-
ation sensor to the ABS control module. Circuits
B515 and B516 provide switch states while circuit
B517 provides ground. At the ABS control module cir-
cuit B515 connects to cavity 25, circuit B516 connects
to cavity 43 and circuit B517 connects to cavity 26.
ABS POWER RELAY
The ABS power relay is located in the power distri-
bution center (PDC). When the ABS module grounds
the ABS power relay on circuit B207, the relay
switches to connect circuit A20 from PDC fuse 10 to
circuit B235. Circuit B236 from fuse 7 in the fuse
block splices to feed the coil side of the ABS power
relay. Circuit B207 connects to cavity 34 of the ABS
control module.
Circuit B235 is double crimped at the ABS power
relay. One branch of circuit B235 supplies power to
the coil side of the ABS pump motor relay. The other
branch of circuit B235 splices to cavities 3 and 33 of
the ABS control module and to the hydraulic control
unit.
ABS PUMP MOTOR RELAY
The ABS pump motor relay in the power distribu-
tion center (PDC) supplies voltage to the ABS pump
motor. When the ABS power relay energizes, circuit
B235 supplies battery voltage to the coil side of the
J8W-32 ANTI-LOCK BRAKESÐXJ-RHD 8W - 32 - 1
Page 873 of 2198

ABS pump motor relay. The ABS control module pro-
vides ground for the relay on circuit B116. Circuit
B116 connects to cavity 15 of the ABS control mod-
ule.
When the ABS pump motor energizes, it connects
circuit A10 from PDC fuse 8 to circuit B233. Circuit
B233 supplies battery voltage to the pump motor.
Circuit Z12 provides ground for the pump motor.
PUMP MOTOR SPEED SENSOR
The input from the pump motor speed sensor tells
the ABS control module that the pump is operating.
Circuits B219 and B220 from the control module con-
nect to the speed sensor.
BRAKE SWITCH INPUT
Circuit L50 from the stop lamp provides the brake
switch input to the ABS control module. When the
brake pedal is depressed, the stop lamp switch closes
to supply battery voltage from circuit L9 to circuit
L50. Circuit L50 connects to cavity 32 of the ABS
control module. Circuit L9 originates at fuse 4 in the
Power Distribution Center (PDC).
HYDRAULIC CONTROL UNIT
When the ABS power relay energizes, two branches
of circuit B235 splice to supply voltage to the isola-
tion and decay solenoids in the hydraulic control
unit. The hydraulic control unit contains three sepa-
rate isolation solenoids and three separate dump so-
lenoids. The ABS control module activates the decay
and isolation solenoids by providing separate ground
paths for each.
The ABS module provides a ground path for the
rear isolation solenoid on circuit B251. Circuit B251
connects to cavity 54 of the ABS control module.
For the right front isolation solenoid, the ABS mod-
ule provides a ground path on circuit B249. Circuit
B249 connects to cavity 38 of the ABS control mod-
ule.
On circuit B245, the ABS control module provides
ground for the left front isolation solenoid. Circuit
B245 connects to cavity 20 of the ABS control mod-
ule.
The ABS control module provides a ground path for
the rear dump solenoid on circuit B254. Circuit B254
connects to cavity 36 of the ABS control module.For the right front dump solenoid, the ABS module
provides a ground path on circuit B248. Circuit B248
connects to cavity 21 of the ABS control module.
On circuit B243, the ABS module provides ground
for the left dump solenoid. Circuit B243 connects to
cavity 2 of the ABS control module.
ABS WARNING LAMP
Circuit F87 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 B205.
Circuit B205 splices to connect to circuit B235
through a diode. When the ABS power relay is not
energized, it connects circuit B235 to circuit Z12. The
ground path for the warning lamp is through the di-
ode to circuit B235, through the ABS power relay to
ground on circuit Z12.
The diode between circuit B205 and B235 prevents
voltage from flowing to the ABS control module when
the ABS power relay switches to supply power on cir-
cuit B235.
DATA LINK CONNECTOR
Circuit D1 from cavity 23 of the ABS control mod-
ule receives data from the DRB scan tool through the
data link connector. The ABS control module trans-
mits data to the scan tool through the connector on
circuit D2. Circuit D2 originates at cavity 42 of the
ABS control module.
Through the data link connector, circuit Z12 pro-
vides ground for the DRB scan tool. Circuit Z12 ter-
minates at the right rear of the engine.
Circuit A4 from fuse 7 in the Power Distribution
Center (PDC) supplies power to fuse 13 in the PDC.
Fuse 13 powers circuit F39 which supplies battery
voltage to the scan tool through the diagnostic con-
nector.
HELPFUL INFORMATION
²Check fuses 7 and 13 in the PDC.
²If the vehicle is equipped with an automatic trans-
mission, circuits D1 and D2 are double crimped at
the data link connector and connect to the Power-
train Control Module (PCM).
8W - 32 - 2 8W-32 ANTI-LOCK BRAKESÐXJ-RHDJ
Page 902 of 2198

AIR CONDITIONING/HEATER
CONTENTS
page page
A/C-HEATER SYSTEM...................... 1 HEATERSYSTEM......................... 1
GENERAL INFORMATION
This section of the wiring diagrams is divided into
two sub-sections; Heater, and A/C and Heater. Whenreferring to the circuit descriptions or wiring dia-
grams, ensure that you use the correct sub-section.
HEATER SYSTEM
BLOWER MOTOR
In the RUN or ACCESSORY position, the ignition
switch connects circuit A1 from fuse 6 in the PDC to
circuit A48. Circuit A48 supplies battery voltage to
fuse 4 in the fuse block. Fuse 4 supplies power to the
heat mode switch on circuit C7.
Circuit C43 from the heat mode switch splices to
supply voltage to the blower motor switch and the
blower motor resistor block. The blower motor switch
sets blower motor speed to HIGH, M1, M2, or LOW.
When the blower motor switch is in the LOW posi-
tion, circuit C43 from the heat mode supplies voltage
to the resistor block. Voltage does not pass through
the blower motor switch in the LOW position.
In the M1 position, the blower motor switch sup-
plies voltage to the resistor block on circuit C4. Fromcircuit C4, voltage passes through three resistors in
the resistor block to the blower motor on circuit C1.
In the M2 position, the blower motor supplies volt-
age to the resistor block on circuit C6. From circuit
C6 voltage flows through two resistors to the blower
motor on circuit C1.
In the HIGH position, the blower motor switch con-
nects directly to the blower motor on circuit C1. Volt-
age does not pass through the resistor block in the
HIGH position.
Circuit Z1 provides ground for the blower motor.
DIAGRAM INDEX
AC/HEATER SYSTEM
GENERAL INFORMATION
Several fuses supply power for the air conditioning/
heater system. In the START or RUN positions, the
ignition switch connects circuit A1 from fuse 6 in the
Power Distribution Center (PDC) to circuit A21. Cir-
cuit A21 powers a bus bar in the PDC that feeds cir-
cuit F12 through fuse 11. Circuit F12 feeds the
contact side of the A/C compressor clutch relay and
the coil side of the radiator fan relay.
In the RUN or ACCESSORY position, the ignition
switch connects circuit A1 from fuse 6 in the PDC to
circuit A48. Circuit A48 supplies battery voltage tofuse 4 in the fuse block. Fuse 4 supplies power to the
A/C-Heater control switch on circuit C7.
Fuse 15 in the PDC supplies battery voltage to the
contact side of the radiator fan relay on circuit F141.
Circuit A14 from fuse 2 in the PDC powers PDC fuse
15.
BLOWER MOTOR
In the RUN or ACCESSORY position, the ignition
switch connects circuit A1 from fuse 6 in the PDC to
circuit A48. Circuit A48 supplies battery voltage to
J8W-42 AIR CONDITIONING/HEATERÐXJ-RHD 8W - 42 - 1
Page 944 of 2198

REAR LIGHTING
TAIL LAMPS AND REAR LICENSE PLATE LAMPS
Circuit A3 from fuse 5 in the Power Distribution
Center (PDC) connects to a bus bar in the fuse block
which feeds circuit L7. Fuse 9 in the fuse block pro-
tects circuit L7.
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 L7 to circuit
L90. From the headlamp switch, circuit L90 branches
to power the front parking lamps and rear tail
lamps, side marker lamps, and rear license plate
lamps.
GROUND CIRCUIT
Circuit Z1 provides a ground for the parking lamps,
tail lamps, and rear license plate lamps.
HELPFUL INFORMATION
²Check fuse 5 in PDC.
²Check fuse 9 in the fuse block.
²When the headlamp switch is in the PARK or ON
position, circuit L7 also connects to circuit E2. Cir-
cuit E2 continues through fuse 25 in the fuse block.
Circuit E2 powers the illumination lamps.
STOP LAMPS AND CHMSL LAMPS
Circuit L9 from fuse 4 in the Power Distribution
Center (PDC) connects to the stop lamp switch.
When the operator depresses the brake pedal, the
stop lamp switch closes and connects circuit L9 to
circuit L50. Circuit L50 connects to the stop lamps
and center high mounted stop lamps (CHMSL). Cir-
cuit Z1 provides a ground for the stop lamps.
HELPFUL INFORMATION
²Check fuses 13 in the PDC.
²Check for continuity across the stop lamp switch
when it is closed.
BACK-UP LAMPS
In the START or RUN position, the ignition switch
connects circuit A1 from fuse 6 in the Power Distri-
bution Center (PDC) to circuit A21. Circuit A21 feeds
a bus bar in the PDC that powers circuit F12
through fuse 11.
Circuit F12 supplies power to the back-up lamp
switch. On automatic transmission equipped vehicles,
the back-up lamp switch is part of an assembly that
includes the PARK/NEUTRAL position switch. When
the operator puts the transmission in REVERSE, the
back-up lamp switch connects circuit F12 to circuit
L10. Circuit L10 feeds the back-up lamps. Circuit Z1
provides ground for the back-up lamps.
HELPFUL INFORMATION
²Check fuses 6 and 11 in the PDC.
²Check for continuity across the back-up lamp
switch when it is closed.
DIAGRAM INDEX
Component Page
Center High Mounted Stop Lamps (CHMSL).......8W-51-3
Fuse 4 (PDC)...........................8W-51-3
Fuse 5 (PDC)...........................8W-51-2
Fuse 6 (Fuse Block).......................8W-51-2
Fuse 6 (PDC)...........................8W-51-2
Fuse 9 (Fuse Block).......................8W-51-2
Headlamp Switch.........................8W-51-2
Ignition Switch..........................8W-51-2
Left Back-Up Lamp.......................8W-51-4
Left Side Marker Lamp.....................8W-51-4
Left Tail/Stop Lamp.......................8W-51-4
Left Turn Signal Lamp.....................8W-51-4
License Plate Lamp.......................8W-51-3
Park/Neutral Position Switch.................8W-51-2
Right Back-Up Lamp......................8W-51-5
Right Side Marker Lamp....................8W-51-5
Right Tail/Stop Lamp......................8W-51-4
Right Turn Signal Lamp....................8W-51-5
Stop Lamp Switch........................8W-51-3
J8W-51 REAR LIGHTINGÐXJ-RHD 8W - 51 - 1
Page 2026 of 2198

FUEL/IGNITION
INDEX
page page
Automatic Shut Down (ASD) Relay............. 1
Battery Feed.............................. 2
Brake Switch Input......................... 5
Camshaft Position Sensor.................... 3
Crankshaft Position Sensor................... 3
Data Link Connector........................ 5
Diagram Index............................ 5
Engine Coolant Temperature Sensor............ 3
Fuel Injectors............................. 2
Fuel Pump Module......................... 2
Fuel Pump Relay.......................... 2
Heated Oxygen Sensor...................... 3Idle Air Control (IAC) Motor................... 2
Ignition Coil.............................. 2
Ignition Switch............................ 1
Intake Air Temperature Sensor................ 4
Malfunction Indicator Lamp (MIL)............... 5
Manifold Absolute Pressure Sensor............. 4
Park/Neutral Position Switch.................. 4
Power (Device) Ground...................... 5
Power Steering Pressure Switch............... 4
Tachometer Signal......................... 5
Throttle Position Sensor..................... 4
Vehicle Speed Sensor....................... 3
IGNITION SWITCH
Circuit A1 from fuse 4 in the Power Distribution
Center (PDC), supplies battery voltage to the ignition
switch. Depending upon position, the ignition switch
powers circuits A21, A22, A31, and A41.
START POSITION
In the START position, the ignition switch connects
circuit A1 to circuit A41. Circuit A41 connects to the
coil side of the starter motor relay.
Also in the START position, the case grounded ig-
nition switch provides ground for the brake lamp
switch and parking brake lamp switch on circuit G11.
START OR RUN POSITION
In the START and RUN position, the ignition
switch connects circuit A1 with circuit A21. The A21
circuit connects to fuses 5 and 9 in the fuse block.
Fuse 9 powers circuit G5. Fuse 5 powers circuit G50.
²Circuit G5 powers the buzzer module. Circuit G5
also splices to power the daytime running lamps
module (Canada only), A/C compressor clutch relay,
heated rear window relay, and the gauges and indi-
cator lamps in the instrument cluster.
RUN (ONLY) POSITION
When the ignition switch is in the RUN position, it
connects circuit A1 to circuit A22. Circuit A22 powers
fuses 1, 12, and 13 in the fuse block.
²Fuse 1 powers the rear wiper system on circuit
V23.
²Fuse 12 feeds the blower motor and air condition-
ing system on circuit C1.
²Fuse 13 feeds circuit F15 which powers the ABS
module and connects to the coil side of the ABS
power relay.
ACCESSORY OR RUN POSITION
In the ACCESSORY or RUN position, the ignition
switch connects circuit A1 to circuit A31. Circuit A31
connects to a bus bar in the fuse block that feeds
fuses 4 and 7 along with the circuit breaker in cavity
11 .
²Fuse 4 powers circuit L5 which feeds the turn sig-
nal flasher.
²Fuse 7 powers circuit F30. Circuit F30 supplies
power to the radio, radio relay, and the cigar lighter.
²The circuit breaker in cavity 11 powers the V6 cir-
cuits which feed the wiper switch and wiper motor.
AUTOMATIC SHUT DOWN (ASD) RELAY
When the ignition switch is in either the START or
RUN position, it connects circuit A1 from fuse 4 in
the Power Distribution Center (PDC) to circuit A21.
Circuit A21 powers fuse 5 in the fuse block. Circuit
G50 from fuse 5 splices to power the coil side of the
Automatic Shut Down (ASD) relay. The Powertrain
Control Module (PCM) provides ground for the relay
on circuit K51. Circuit K51 connects to cavity 51 of
the PCM.
When the PCM grounds the ASD relay, contacts in-
side the relay close and connect circuit A14 from fuse
1 in the PDC to circuit A142. Circuit A142 splices to
the generator field terminal, fuel injectors, ignition
coil, and heated oxygen sensor. Circuit A142 also con-
nects to cavity 57 of the PCM.
Circuit A14 from fuse 1 in the PDC supplies bat-
tery voltage to the contact side of the ASD relay.
HELPFUL INFORMATION
²Along with supplying voltage to the ASD relay
contacts, circuit A14 supplies voltage to the contact
side of the fuel pump relay.
²Circuit G50 also supplies battery voltage to the
coil side of the fuel pump relay.
²Circuit A14 also connects to cavity 3 of the PCM.
J8W-30 FUEL/IGNITIONÐYJ VEHICLES 8W - 30 - 1
Page 2050 of 2198

ANTI-LOCK BRAKES
GENERAL INFORMATION
Three fuses supply power for the Anti-Lock Brake
System (ABS); fuses 9 and 10 in the PDC and fuse
13 in the fuse block. Fuses 9 and 10 in the Power
Distribution Center (PDC) are connected directly to
battery voltage and are HOT all times. Fuse 13 is
HOT when the ignition switch is the RUN position.
In the RUN position, the ignition switch connects
circuit A1 from fuse 4 in the PDC with circuit A22.
Circuit A22 connects to a bus bar in the fuse block.
The bus bar feeds circuit F15 through fuse 13. Fuse
13 is a 2 amp fuse.
Circuit F15 splices to the coil side of the ABS
power relay and cavity 53 of the ABS control module.
Circuit Z1 provides ground for the ABS control
module. Circuit Z1 connects to cavities 1 and 19 of
the ABS control module.
Refer to group 5, Brakes for operational descrip-
tions of ABS system components.
WHEEL SPEED SENSORS
The all wheel anti-lock system uses four wheel
speed sensors; one for each wheel. Each sensor con-
verts wheel speed into an electrical signal that it
transmits to the ABS control module. A pair of
twisted wires connect to each sensor to provide sig-
nals to the ABS control module.
Circuits B6 and B7 provide signals to ABS control
module from the right front wheel speed sensor. Cir-
cuit B6, which provides the LOW signal, connects to
cavity 29 of the ABS control module. Circuit B7 con-
nects to cavity 47 of the module and provides the
HIGH signal.
Circuits B8 and B9 provide signals to ABS control
module from the left front wheel speed sensor. Cir-
cuit B8, which provides the LOW signal, connects to
cavity 30 of the ABS control module. Circuit B9 con-
nects to cavity 48 of the module and provides the
HIGH signal.
Circuits B1 and B2 provide signals to ABS control
module from the right rear wheel speed sensor. Cir-
cuit B1 which provides the LOW signal, connects to
cavity 27 of the ABS control module. Circuit B2 con-
nects to cavity 45 of the module and provides the
HIGH signal.
Circuits B4 and B3 provide signals to ABS control
module from the left rear wheel speed sensor. Circuit
B3, which provides the LOW signal, connects to cav-
ity 28 of the ABS control module. Circuit B4 connects
to cavity 46 of the module and provides the HIGH
signal.
ACCELERATION SWITCH
During four-wheel drive operation, the acceleration
switch provides deceleration data to the ABS control
module. Refer to Group 5, Brakes for additional in-
formation.
Circuits B21, B22, and B23 connect the accelera-
tion sensor to the ABS control module. Circuits B21
and B22 provide switch states while circuit B23 pro-
vides ground. At the ABS control module circuit B21
connects to cavity 25, circuit B22 connects to cavity
43 and circuit B23 connects to cavity 26.
ABS POWER RELAY
The ABS power relay is located in the Power Dis-
tribution Center (PDC). When the ABS module
grounds the ABS power relay on circuit B20, the re-
lay switches to connect circuit B15 and circuit A20
from PDC fuse 10. Circuit F15 from fuse 13 in the
fuse block splices to feed the coil side of the ABS
power relay. Circuit B20 connects to cavity 34 of the
ABS control module.
Circuit B15 is double crimped at the ABS power re-
lay. One branch of circuit B15 supplies power to the
coil side of the ABS pump motor relay. The other
branch of circuit B15 splices to cavities 3 and 33 of
the ABS control module and to the hydraulic control
unit.
ABS PUMP MOTOR RELAY
The ABS pump motor relay in the Power Distribu-
tion Center (PDC) supplies voltage to the ABS pump
motor. When the ABS power relay energizes, circuit
B15 supplies battery voltage to the coil side of the
ABS pump motor relay. The ABS control module pro-
vides ground for the relay on circuit B116. Circuit
B116 connects to cavity 15 of the ABS control mod-
ule.
When the ABS pump motor energizes, it connects
circuit A10 from PDC fuse 9 to circuit B25. Circuit
B25 supplies battery voltage to the pump motor. Cir-
cuit Z12 provides ground for the pump motor.
PUMP MOTOR SPEED SENSOR
The input from the pump motor speed sensor tells
the ABS control module that the pump is operating.
Circuit B17 and B16 from the control module connect
to the speed sensor.
BRAKE PEDAL TRAVEL SENSOR
The brake pedal travel sensor provides the ABS
control module with data regarding brake pedal posi-
tion. The sensor is a variable resistor that the ABS
J8W-32 ANTI-LOCK BRAKESÐYJ VEHICLES 8W - 32 - 1