light JEEP CHEROKEE 1995 Service Repair Manual

nal B (driver side) with the positive lead. The volt-
meter should read 10-14 volts.
Steps 3, 4 or 5 above will confirm system operation.
Indicator light illumination means that there is
power available at the output of the switch, but does
not confirm that power is reaching the rear window
grid lines.
If the rear window defogger does not operate, the
problem should be isolated in the following manner:
(1) Confirm that ignition switch is in ON position.
(2) Ensure that the heated rear window feed and
ground wires are connected to the glass. Confirm
that the ground wire has continuity to ground.
(3) Check fuses 8 and 18 (XJ), or fuses 6 and 9
(YJ) in fuseblock module. Fuses must be tight in
their receptacles and all electrical connections must
be secure.
When the above steps have been completed and the
system is still inoperative, one or more of the follow-
ing is faulty:
²defogger switch²relay/timer
²rear window grid lines (all grid lines would have
to be broken or one of the feed wires disconnected for
the entire system to be inoperative).
If turning the switch ON produces severe voltmeter
deflection, check for a short circuit.
REAR WINDOW GLASS GRID
To detect breaks in grid lines, the following proce-
dure is required:
(1) Turn ignition switch to the ON position. Turn
rear defogger switch ON. The indicator lamp should
light.
(2) Using a 12-volt DC voltmeter, contact vertical
bus bar on passenger side of vehicle (point A of Fig.
1) with negative lead of voltmeter. With positive lead
of voltmeter, contact vertical bus bar on driver side of
vehicle (point B of Fig. 1). The voltmeter should read
10-14 volts.
(3) With negative lead of voltmeter, contact a good
body ground point. The voltage reading should not
change. A different reading indicates a poor ground
connection.
(4) Connect negative lead of voltmeter to point A
on passenger side bus bar and touch each grid line at
mid-point with positive lead. A reading of approxi-
mately 6 volts indicates a line is good. A reading of
zero volts indicates a break in the grid line between
mid-point C and point B. A reading of 10-14 volts in-
dicates a break between mid-point C and point A.
Move toward break and voltage will change as soon
as break is crossed.
Fig. 1 Rear Window Glass Grid Test
8N - 2 REAR WINDOW DEFOGGERJ

(9) Allow epoxy to cure 24 hours at room tempera-
ture or use heat gun with a 260É-371ÉC (500É-700ÉF)
range for 15 minutes. Hold gun approximately
254mm (10 inches) from repaired area.
(10) After conductive epoxy is properly cured re-
move wedge or clamp from terminal or pigtail and
check operation of rear window defogger. Do not at-
tach connectors until curing is complete.
DEFOGGER SWITCH REMOVE/INSTALL
XJ MODELS
(1) Remove the instrument cluster bezel. Refer to
Group 8E - Instrument Panel and Gauges for proce-
dure.
(2) Remove the switch housing panel.
(3) Unplug the switch connector. Slightly depress
the switch mounting tabs and remove the switch.
(4) Reverse removal procedures to install.
YJ MODELS
(1) Remove 6 bezel screws (Fig. 3).
(2) Slide bezel toward the steering wheel.
(3) Remove 3 screws (Fig. 4).
(4) Unplug the connector from the defogger switch.
(5) Squeeze the ends of the switch to release the
plastic retaining fingers and push outward.
(6) Reverse removal procedures to install.
DEFOGGER RELAY/TIMER REMOVE/INSTALL
XJ MODELS
The rear defogger relay is in the relay center. The
relay center is located on the lower instrument panel
trim cover just right of the steering column.
(1) Remove the rear defogger relay (red) from the
relay center (Fig. 5).
(2) Reverse removal procedures to install.
YJ MODELS
The rear defogger relay is located behind the park-
ing brake pedal in the left cowl side area. Unplug re-
lay from connector and replace with new relay. Be
certain that relay is taped back into place on harness
with plastic cover facing up and terminals facing
down.
Fig. 3 Instrument Bezel Remove/InstallÐYJ
Fig. 4 Defogger Switch Remove/InstallÐYJ
Fig. 5 Rear Defogger RelayÐXJ
8N - 4 REAR WINDOW DEFOGGERJ

POWER LOCK MOTOR
(1) Once it is determined which lock motor is inop-
erative, that motor can be tested. Disconnect the wire
connector at the motor. Apply 12 volts to the motor
terminals to check its operation in one direction. Re-
verse the polarity to check the operation in the other
direction. If OK, repair circuits to power lock/unlock
relays as required. If not OK, replace the motor.
(2) If all lock motors are inoperative, the problem
may be caused by one shorted motor. Disconnecting a
shorted motor will allow the good motors to operate.
Disconnect each motor connector, one at a time, and
re-check both lock and unlock functions while operat-
ing the door lock switch. If disconnecting one motor
causes the other motors to become functional, go
back to step 1 to test the disconnected motor.
KEYLESS ENTRY TRANSMITTER
(1) Depress either transmitter button and note
whether red Light-Emitting Diode (LED) on trans-
mitter case lights. If OK, go to next step. If not OK,
replace batteries as described under Keyless Entry
Transmitter in Service Procedures. Test transmitter
operation. If OK, discard faulty batteries. If not OK,
go to next step.
(2) Perform transmitter program procedure with
suspect transmitter and another known good trans-
mitter, as described in Service Procedures. Test oper-
ation with both transmitters. If both transmitters fail
to operate power locks, see Keyless Entry Module di-
agnosis. If known good transmitter operates power
locks and suspect transmitter does not, replace faulty
transmitter. Be certain to perform transmitter pro-
gram procedure again when replacing faulty trans-
mitter and to erase test transmitter access code from
keyless entry module.
KEYLESS ENTRY MODULE
(1) Check fuse 9 in fuseblock module. If OK, go to
next step. If not OK, replace fuse.
(2) Check for battery voltage at fuse 9. If OK, go to
next step. If not OK, repair circuit from power distri-
bution center.
(3) Access keyless entry module connectors as de-
scribed in Keyless Entry Module Remove/Install.
(4) Unplug module connector from module. Check
connector and receptacle in module for loose, cor-
roded, or damaged terminals and pins. If OK, go to
next step. If not OK, repair as required.
(5) Probe connector cavity for module terminal 1
and check for battery voltage. If OK, go to next step.
If not OK, repair circuit to fuse 9 as required.
(6) Install a jumper wire from connector cavity for
module terminal 1 to connector cavity for module ter-
minal 3. Doors should lock. If OK, go to step 8. If not
OK, go to next step.
(7) Check for continuity between connector cavity
for module terminal 3 and lock relay terminal 3 (86).
There should be continuity. If OK, replace lock relay.
If not OK, repair circuit as required.
(8) Install a jumper wire from connector cavity for
module terminal 1 to connector cavity for module ter-
minal 4. Doors should unlock. If OK, replace module.
If not OK, go to next step.
(9) Check for continuity between connector cavity
for module terminal 4 and unlock relay terminal 3
(86). There should be continuity. If OK, replace un-
lock relay. If not OK, repair circuit as required.
JPOWER LOCKS 8P - 7

POWER WINDOWS
CONTENTS
page page
DIAGNOSIS............................. 1
GENERAL INFORMATION.................. 1SERVICE PROCEDURES................... 7
GENERAL INFORMATION
Power door windows are optional equipment on XJ
(Cherokee) models. The power windows operate only
with the ignition switch in the ON position. This
group covers diagnosis and service of the electrical
components peculiar to the power window system.
For service of mechanical components such as the
regulator, lift plate or window tracks refer to Group
23 - Body Components.
Following are general descriptions of the major
components in the power window system. Refer to
Group 8W - Wiring Diagrams for complete circuit de-
scriptions and diagrams.
POWER WINDOW SWITCH
Both front and rear door windows can be raised or
lowered electrically by operating the four two-way
switches on the driver's door panel. A single two-way
switch on each passenger's door panel operates only
the window on that passenger's door. The switches
cannot be repaired. If faulty, they must be replaced.
POWER WINDOW MOTOR
A permanent magnet reversible motor moves the
window regulator through a cable and drum operat-ing mechanism. A positive and negative battery con-
nection to the two motor terminals will cause the
motor to rotate in one direction. Reversing current
through these same two connections will cause the
motor to rotate in the opposite direction. In addition,
each power window motor is equipped with an inte-
gral automatic re-setting circuit breaker to protect
the motor from overloads. The power window motor
and regulator assembly cannot be repaired. If faulty,
the entire assembly must be replaced.
CIRCUIT BREAKER
An automatic re-setting circuit breaker in the fuse-
block module is used to protect the power window
system circuit. The circuit breaker can protect the
system from a short circuit, and can also protect the
system from an overload condition caused by an ob-
structed or stuck window glass or regulator. The cir-
cuit breaker can not be repaired. If faulty, it must be
replaced.
DIAGNOSIS
It is necessary that the window be free to slide up
and down for the power window system to function
properly. If the window is not free to move up and
down, the motor will overload and trip the circuit
breaker. To determine if the glass is free, disconnect
regulator plate from the glass and slide window up
and down by hand.
An alternate method is to shake the glass in the
door, with the glass positioned between the up and
down stop positions. Check that the glass can be
moved slightly from side to side, front to rear, and up
and down. Then check that window is not boundtight in the tracks. If window is free, proceed with di-
agnosis that follows. If window is not free, refer to
Group 23 - Body Components for service procedures.
CIRCUIT BREAKER
Locate correct circuit breaker in fuseblock module.
Pull out slightly, but be sure that circuit breaker ter-
minals still contact terminals in fuseblock module.
Turn ignition switch to ON position. Connect ground
wire of voltmeter to a good ground. With probe of
voltmeter positive lead, check both terminals of cir-
cuit breaker for battery voltage. If only one terminal
JPOWER WINDOWS 8S - 1

DIAGNOSIS
BUZZER MODULE
(1) Check fuses (15 and 17 - XJ, 3 and 9 - YJ) in
the fuseblock module. If fuses are OK, go to next
step. If not OK, replace fuses as required.
(2) Check for battery voltage at fuse (15 - XJ, 3 -
YJ) in fuseblock module. If OK, go to next step. If not
OK, repair feed circuit from power distribution center
as required.
(3) Turn ignition switch to ON position. Check for
battery voltage at fuse (17 - XJ, 9 - YJ) in the fuse-
block module. If OK, go to next step. If not OK, re-
pair feed from ignition switch as required.
(4) Turn ignition switch to OFF position. Replace
buzzer module with a known good unit and test op-
eration. If not OK, remove buzzer module and go to
next step.
(5) Check for battery voltage at cavity for buzzer
terminal 7 in buzzer module connector (Fig. 1). If
OK, go to next step. If not OK, repair circuit to fuse
(15 - XJ, 3 - YJ).
(6) Turn ignition switch to ON position. Check for
battery voltage at cavity for buzzer terminal 1 in
buzzer module connector. If OK, go to next step. If
not OK, repair circuit to fuse (17 - XJ, 9 - YJ) in fuse-
block module.
(7) Turn ignition switch to OFF position. Check for
continuity between cavity for buzzer terminal 3 and
a good ground. There should be continuity. If OK, go
to diagnosis for switch that is related to buzzer mal-
function. If not OK, repair circuit to ground as re-
quired.
DRIVER'S DOOR JAMB SWITCH
(1) Open driver's door and note whether interior
lamps light. They should light. If OK, see diagnosis
for Ignition Key-In Switch (XJ or YJ) or Headlamp
Switch (XJ only). If not OK, go to next step.
(2) Check for continuity between door jamb switch
body and a good ground. There should be continuity.
If OK, go to next step. If not OK, tighten or clean
switch attachment to hinge pillar as required to re-
store ground path.
(3) Remove switch from hinge pillar and check
wire connections for clean and tight engagement. If
OK, replace faulty switch. If not OK, clean and
tighten connections as required.
IGNITION KEY-IN SWITCH
XJ MODELS
(1) Remove steering column shrouds (refer to
Group 8D - Ignition Systems for procedure). Unplug
ignition key-in switch connector from ignition switch
(Fig. 3). Open driver's door. Check for continuity be-
tween cavity 4 (black/light blue wire) and a good
ground. There should be continuity. If OK, go to next
step. If not OK, repair circuit to driver's door jamb
switch as required.
(2) Insert ignition key in ignition lock cylinder.
Check for continuity between key-in switch cavities 3
and 4 (Fig. 4). There should be continuity until key is
removed. If OK, go to next step. If not OK, replace
ignition switch.
(3) Check for continuity between key-in switch har-
ness connector cavity 3 (light blue wire) and cavity
for terminal 6 of buzzer module in buzzer module
connector. There should be continuity. If not OK, re-
pair circuit from switch to buzzer module as re-
quired.
Fig. 1 Buzzer Module Connector
Fig. 2 Buzzer Module Terminals
8U - 2 CHIME/BUZZER WARNING SYSTEMSJ

YJ MODELS
(1) Unplug steering column connector from instru-
ment panel wiring. Open driver's door. Check for con-
tinuity between cavity E (black/light blue wire) in
instrument panel half of steering column connector
and a good ground. There should be continuity. If
OK, go to next step. If not OK, repair circuit to driv-
er's door jamb switch as required.
(2) Insert ignition key in ignition lock cylinder.
Check for continuity between cavities E (pink wire)
and F (black wire) in steering column half of connec-
tor. There should be continuity until key is removed.
If OK, go to next step. If not OK, repair steering col-
umn wiring or replace key-in switch as required.
(3) Check for continuity between cavity F (light
blue wire) in instrument panel half of steering col-
umn connector and cavity for terminal 6 of buzzer
module in buzzer module connector. There should be
continuity. If not OK, repair circuit from switch to
buzzer module as required.
HEADLAMP SWITCH (XJ ONLY)
(1) Remove headlamp switch from instrument
panel (refer to Group 8E - Instrument Panel and
Gauges for procedure). Unplug headlamp switch con-
nector. Open driver's door. Check for continuity be-
tween headlamp switch connector cavity with light
blue wire and a good ground. There should be conti-
nuity until driver's door is closed. If OK, go to next
step. If not OK, repair circuit from headlamp switch
to driver's door jamb switch as required.
(2) Check for continuity between headlamp switch
connector cavity with pink/light blue wire and cavity
for terminal 6 of buzzer module in buzzer module
connector. There should be continuity. If OK, go to
next step. If not OK, repair circuit from headlamp
switch to buzzer module as required.
(3) Check continuity between headlamp switch ter-
minal for connector cavity with pink/light blue wire
and terminal for cavity with light blue wire. There
should be no continuity with switch in off position,
and there should be continuity with switch in park
lamps or headlamps on position. If not OK, replace
headlamp switch.
DRIVER'S SEAT BELT SWITCH
(1) Unplug seat belt switch connector on floor un-
der driver's seat riser near seat belt anchor. Check
for continuity between two cavities of seat belt half of
connector. There should be continuity with seat belt
unbuckled, and no continuity with seat belt buckled.
If OK, go to next step. If not OK, replace seat belt
buckle-half assembly.
(2) Check for continuity between cavity with black
wire in harness half of seat belt switch connector and
a good ground. There should be continuity. If OK, go
to next step. If not OK, repair circuit to ground as re-
quired.
(3) Check for continuity between cavity with light
green wire in harness half of seat belt switch connec-
tor and cavity for terminal 4 of buzzer module con-
nector. There should be continuity. If not OK, repair
circuit from seat belt switch connector to buzzer mod-
ule as required.
Fig. 3 Key-In Switch Connector
Fig. 4 Key-In Switch Continuity
JCHIME/BUZZER WARNING SYSTEMS 8U - 3

(2) Connect the other lead of the voltmeter to the
selected test point. The vehicle ignition may need to
be turned ON to check voltage. Refer to the appropri-
ate test procedure.
TESTING FOR CONTINUITY
(1) Remove the fuse for the circuit being checked or,
disconnect the battery.
(2) Connect one lead of the ohmmeter to one side of
the circuit being tested (Fig. 9).
(3) Connect the other lead to the other end of the
circuit being tested. Low or no resistance means good
continuity.
TESTING FOR A SHORT TO GROUND
(1) Remove the fuse and disconnect all items in-
volved with the fuse.
(2) Connect a test light or a voltmeter across the
terminals of the fuse.
(3) Starting at the fuse block, wiggle the wiring
harness about six to eight inches apart and watch the
voltmeter/test lamp.
(4) If the voltmeter registers voltage or the test
lamp glows, there is a short to ground in that general
area of the wiring harness.
TESTING FOR A SHORT TO GROUND ON
FUSES POWERING SEVERAL LOADS
(1) Refer to the wiring diagrams and disconnect or
isolate all items on the fused circuit.
(2) Replace the blown fuse.
(3) Supply power to the fuse by turning ON the
ignition switch or re-connecting the battery.(4) Start connecting the items in the fuse circuit
one at a time. When the fuse blows the circuit with
the short to ground has been isolated.
TESTING FOR A VOLTAGE DROP
(1) Connect the positive lead of the voltmeter to the
side of the circuit closest to the battery (Fig. 10).
(2) Connect the other lead of the voltmeter to the
other side of the switch or component.
(3) Operate the item.
(4) The voltmeter will show the difference in volt-
age between the two points.
TROUBLESHOOTING WIRING PROBLEMS
When troubleshooting wiring problems there are six
steps which can aid in the procedure. The steps are
listed and explained below. Always check for non-
factory items added to the vehicle before doing any
diagnosis. If the vehicle is equipped with these items,
disconnect them to verify these add-on items are not
the cause of the problem.
(1) Verify the problem.
(2) Verify any related symptoms. Do this by per-
forming operational checks on components that are in
the same circuit. Refer to the wiring diagrams.
(3) Analyze the symptoms. Use the wiring dia-
grams to determine what the circuit is doing, where
the problem most likely is occurring and where the
diagnosis will continue.
(4) Isolate the problem area.
(5) Repair the problem.
(6) Verify proper operation. For this step, check for
proper operation of all items on the repaired circuit.
Refer to the wiring diagrams.
Fig. 8 Testing for Voltage
Fig. 9 Testing for Continuity
JWIRING DIAGRAMSÐGENERAL INFORMATION 8W - 5

WIRING DIAGRAMS
CONTENTS
page page
8W-01 GENERAL INFORMATIONÐWIRING
DIAGRAMS.................... 8W-01-1
8W-10 FUSE/FUSE BLOCK........... 8W-10-1
8W-11 POWER DISTRIBUTION........ 8W-11-1
8W-15 GROUND DISTRIBUTION....... 8W-15-1
8W-20 CHARGING SYSTEM.......... 8W-20-1
8W-21 STARTING SYSTEM........... 8W-21-1
8W-30 FUEL/IGNITION.............. 8W-30-1
8W-31 TRANSMISSION CONTROLS.... 8W-31-1
8W-32 ANTI-LOCK BRAKES.......... 8W-32-1
8W-33 VEHICLE SPEED CONTROL..... 8W-33-1
8W-40 INSTRUMENT CLUSTER....... 8W-40-1
8W-41 HORN/CIGAR LIGHTER......... 8W-41-1
8W-42 AIR CONDITIONING/HEATER.... 8W-42-1
8W-44 INTERIOR LIGHTING.......... 8W-44-1
8W-47 AUDIO SYSTEM.............. 8W-47-18W-48 HEATED REAR WINDOW....... 8W-48-1
8W-49 OVERHEAD CONSOLE......... 8W-49-1
8W-50 FRONT LIGHTING............. 8W-50-1
8W-51 REAR LIGHTING............. 8W-51-1
8W-52 TURN SIGNALS.............. 8W-52-1
8W-53 WIPERS..................... 8W-53-1
8W-54 TRAILER TOW................ 8W-54-1
8W-60 POWER WINDOWS.......... 8W-60-1
8W-61 POWER DOOR LOCKS......... 8W-61-1
8W-62 POWER MIRRORS............ 8W-62-1
8W-63 POWER SEAT................ 8W-63-1
8W-70 SPLICE INFORMATION........ 8W-70-1
8W-80 CONNECTOR PIN OUTS....... 8W-80-1
8W-90 CONNECTOR LOCATIONS...... 8W-90-1
8W-95 SPLICE LOCATIONS........... 8W-95-1
HOW TO USE THIS GROUP
The purpose of this group is to show the electrical
circuits in a clear, simple fashion and to make trou-
bleshooting easier. Components that work together
are shown together. All electrical components used in
a specific system are shown on one diagram. The feed
for a system is shown at the top of the page. All
wires, connectors, splices, and components are shown
in the flow of current to the bottom of the page. Wir-
ing which is not part of the circuit represented is ref-
erenced to another page/section, where the complete
circuit is shown. In addition, all switches, compo-
nents, and modules are shown in theat rest posi-
tion with the doors closed and the key removed
from the ignition.
If a component is part of several different circuits,
it is shown in the diagram for each. For example, the
headlamp switch is the main part of the exterior
lighting, but it also affects the interior lighting and
the chime warning system.
It is important to realize that no attempt is
made on the diagrams to represent components
and wiring as they appear on the vehicle. For
example, a short piece of wire is treated the
same as a long one. In addition, switches and
other components are shown as simply as pos-
sible, with regard to function only.
The wiring diagram show circuits for all wheel-
bases. If there is a difference in systems or compo-
nents between wheel-bases, an identifier is placed
next to the component.
SECTION IDENTIFICATION
Sections in Group 8W are organized by sub-sys-
tems. The sections contain circuit operation descrip-
tions, helpful information, and system diagrams. The
intention is to organize information by system, con-
sistently from year to year.
CONNECTOR LOCATIONS
Section 8W-90 contains Connector Location illus-
trations. The illustrations contain the connector
number and component identification. Connector Lo-
cation charts in Section 8W-90 reference the illustra-
tion number for components and connectors.
Section 8W-80 shows each connector and the cir-
cuits involved with that connector. The connectors
are identified using the number on the Diagram
pages.
SPLICE LOCATIONS
Splice Location charts in Section 8W-70 show the
entire splice, and provide references to other sections
the splice serves.
Section 8W-95 contains illustrations that show the
general location of the splices in each harness. The
illustrations show the splice by number, and provide
a written location.
JWIRING DIAGRAMSÐXJ VEHICLES 8W - 1 - 1

Circuit G7 from the vehicle speed sensor provides
an input signal to the PCM. The G7 circuit connects
to cavity 47 of the PCM.
The PCM provides a ground for the vehicle speed
sensor signal (circuit G7) through circuit K4. Circuit
K4 connects to cavity 4 of the PCM.
HELPFUL INFORMATION
²Circuit G7 splices to the speedometer, and daytime
running lights module (DRL).
²Circuit K7 splices to supply 8 volts to the camshaft
position sensor and crankshaft position sensor.
Circuit K4 splices to supply ground for the signals
from the following:
²Heated oxygen sensor
²Camshaft position sensor
²Crankshaft position sensor
²Throttle position sensor
²Manifold absolute pressure sensor
²Engine coolant temperature sensor
²Intake air temperature sensor
HEATED OXYGEN SENSOR
When the fuel pump relay contacts close, they con-
nect circuits A14 and A141. Circuit A141 splices to
supply voltage to the heated oxygen sensor.
Circuit K41 delivers the signal from the heated ox-
ygen sensor to the PCM. Circuit K41 connects to cav-
ity 41 of the PCM.
The PCM provides a ground for the heated oxygen
sensor signal (circuit K41) through circuit K4. Circuit
K4 connects to cavity 4 of the PCM connector.
Circuit Z12 provides a ground for the heater circuit
in the sensor.
Circuit Z12 terminates at the right side of the en-
gine.
HELPFUL INFORMATION
²Circuit A141 also supplies battery voltage to the
fuel pump.
Circuit K4 splices to supply ground for the signals
from the following:
²Heated oxygen sensor
²Camshaft position sensor
²Crankshaft position sensor
²Intake air temperature sensor
²Throttle position sensor
²Manifold absolute pressure sensor
²Engine coolant temperature sensor
²Vehicle speed sensor
CAMSHAFT POSITION SENSOR
The Powertrain Control Module (PCM) supplies 8
volts to the camshaft position sensor (in distributor)
on circuit K7. Circuit K7 connects to cavity 7 of the
PCM.The PCM receives the camshaft position sensor sig-
nal on circuit K44. Circuit K44 connects to cavity 44
of the PCM.
The PCM provides a ground for the camshaft posi-
tion sensor signal (circuit K44) through circuit K4.
Circuit K4 connects to cavity 4 of the PCM.
HELPFUL INFORMATION
²Circuit K7 splices to supply 8 volts to the crank-
shaft position sensor and the vehicle speed sensor.
Circuit K4 splices to supply ground for the signals
from the following:
²Heated oxygen sensor
²Camshaft position sensor
²Crankshaft position sensor
²Intake air temperature sensor
²Throttle position sensor
²Manifold absolute pressure sensor
²Engine coolant temperature sensor
²Vehicle speed sensor
CRANKSHAFT POSITION SENSOR
The Powertrain Control Module (PCM) supplies 8
volts to the crankshaft position sensor on circuit K7.
Circuit K7 connects to cavity 7 of the PCM.
The PCM receives the crankshaft position sensor
signal on circuit K24. Circuit K24 connects to cavity
24 of the PCM.
The PCM provides a ground for the crankshaft po-
sition sensor (circuit K24) through circuit K4. Circuit
K4 connects to cavity 4 of the PCM.
HELPFUL INFORMATION
²Circuit K7 splices to supply 8 volts to the camshaft
position sensor and the vehicle speed sensor.
Circuit K4 splices to supply ground for the signals
from the following:
²Heated oxygen sensor
²Camshaft position sensor
²Crankshaft position sensor
²Intake air temperature sensor
²Throttle position sensor
²Manifold absolute pressure sensor
²Engine coolant temperature sensor
²Vehicle speed sensor
ENGINE COOLANT TEMPERATURE SENSOR
The engine coolant temperature sensor provides an
input to the Powertrain Control Module (PCM) on
circuit K2. From circuit K2, the engine coolant tem-
perature sensor draws up to 5 volts from the PCM.
The sensor is a variable resistor. As coolant temper-
ature changes, the resistance in the sensor changes,
causing a change in current draw. The K2 circuit
connects to cavity 2 of the PCM.
J8W-30 FUEL/IGNITIONÐXJ VEHICLES 8W - 30 - 3

INSTRUMENT CLUSTER
INDEX
page page
ABS Warning Lamp........................ 2
Brake Warning Lamp....................... 2
Charging System Indicator Lamp............... 3
Cluster Ground............................ 3
Diagram Index............................. 3
Engine Coolant Temperature Gauge............ 1
Engine Coolant Temperature Warning Lamp...... 1
Fuel Gauge.............................. 1
High-Beam Indicator Lamp................... 2
Instrument Cluster......................... 1Low Fuel Warning Lamp..................... 1
Low Washer Fluid Warning Lamp.............. 2
Malfunction Indicator Lamp (MIL)............... 2
Manual Transmission Up-Shift Lamp............ 2
Oil Pressure Gauge........................ 2
Oil Pressure Warning Lamp.................. 2
Seat Belt Indicator Warning Lamp.............. 2
Speedometer............................. 2
Tachometer.............................. 2
Turn Signal Indicator Lamps.................. 2
INSTRUMENT CLUSTER
The instrument cluster contains the gauges and
warning lamps. All gauges have magnetic move-
ments.
When the ignition switch is in the START or RUN
position, circuit A21 feeds circuit F87 through fuse 17
in the fuse block. Circuit A1 from fuse 6 in the Power
Distribution Center (PDC) supplies voltage to circuit
A21. Circuit A1 is HOT at all times.
Circuit F87 connects to the cluster connector to
power the gauges and to the telltale connector to
power the warning lamps.
Circuit E2 from fuse 19 in the fuse block feeds the
illumination lamps. Circuit E2 originates at the head-
lamp switch and continues through fuse 19. The
headlamp switch powers circuit E2 when the parking
lamps or headlamp are ON.
Circuit Z2 provides ground for the indicator lamps
and illumination lamps.
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 F87 connects to the instrument
cluster left connector and supplies voltage for the
gauge.
The gauge uses two coils. Current passing through
the coils creates a magnetic field. Position of the
gauge needle is controlled by the amount of current
passing through the coils to ground at the sensor.
ENGINE COOLANT TEMPERATURE WARNING
LAMP
Circuit G20 connects the engine coolant tempera-
ture warning lamp to the engine coolant temperature
switch. When the switch closes, battery voltage from
circuit F87 flows through the lamp to ground through
the switch on circuit G20. The engine coolant tem-
perature switch is case grounded to the engine. Cir-cuit F87 connects to the instrument cluster connector
and supplies voltage for the lamp.
Circuit G20 also connects to the warning lamp to
ground when the ignition switch is in the START
position. When the ignition switch is in the START
position, the lamp illuminates for a bulb test.
FUEL GAUGE
The fuel level sensor is a variable resistor. Circuit
G4 connects the fuel level sensor to the fuel gauge in
the instrument cluster. Circuit F87 from fuse 17 in
the fuse block supplies voltage to the fuel gauge. The
fuel level sensor draws voltage from circuit F87
through the fuel gauge on circuit G4. Circuit G4
connects to circuit 57 in the fuel pump module har-
ness. Circuit 57 connects to the fuel level sensor.
Circuit 99 in the fuel pump module harness con-
nects to circuit Z1. Circuit Z1 provides the ground
path for the fuel level sensor. The grounding point for
circuit Z1 is the left side of the cowl panel.
As current flows through the coils in the fuel gauge,
it creates a magnetic field. One of the coils in the
gauge receives fixed current. The other coil is con-
nected to the level sensor. The magnetic field controls
the position of the fuel gauge pointer.
The fuel level sensor contains a variable resistor. As
the position of the float arm on the fuel level sensor
changes, the resistor changes the current flow
through second coil in the fuel gauge. A change in
current flow alters the magnetic field in the fuel
gauge, which changes the pointer position.
LOW FUEL WARNING LAMP
Circuit G4 connects the fuel level sensor to the fuel
gauge. The low fuel level module at the rear of the
gauge monitors resistance in circuit G4. The low fuel
level module powers an light emitting diode (LED)
when the resistance in circuit G4 reaches a calibrated
level. The LED illuminates the Low Fuel indicator.
Refer to Group 8E for additional information.
J8W-40 INSTRUMENT CLUSTERÐXJ VEHICLES 8W - 40 - 1