wiring JEEP CHEROKEE 1995 Service Repair Manual

SHIFT MOTORÐREMOVAL/DISASSEMBLY
(1) Disconnect the vacuum and wiring connector
from the shift housing.
(2) Remove indicator switch.
(3) Remove the shift motor housing cover, gasket
and shield from the housing (Fig. 11).
(4) Remove the E-clips from the shift motor hous-
ing and shaft. Remove shift motor and shift fork from
the housing (Fig. 12).
(5) Remove the O-ring seal from the shift motor
shaft.
(6) Clean and inspect all components. If any com-
ponent is excessively worn or damaged, it should be
replaced.
ASSEMBLY/INSTALLATION
(1) Install a new O-ring seal on the shift motor
shaft.
(2) Insert the shift motor shaft through the hole in
the housing and shift fork. The shift fork offset
should be toward the differential.(3) Install the E-clips on the shift motor shaft and
housing.
(4) Install the shift motor housing gasket and
cover.Ensure the shift fork is correctly guided
into the shift collar groove.
(5) Install the shift motor housing shield and at-
taching bolts. Tighten the bolts to 11 Nzm (101 in.
lbs.) torque.
(6) Add 148 ml (5 ounces) of API grade GL 5 hy-
poid gear lubricant to the shift motor housing. Add
lubricant through indicator switch mounting hole.
(7) Install indicator switch, electrical connector
and vacuum harness.
INTERMEDIATE AXLE SHAFTÐREMOVAL/
DISASSEMBLY
Service to the Disconnect axle seals and bearing re-
quire the use of Tool Set 6288 (J34659) and Seal In-
staller 6228.
(1) Remove the vacuum motor housing. Refer to
Shift Motor Removal in this section.
(3) Remove the outer axle shaft. Refer to Hub
Bearing and Axle Shaft in this section.
(4) Remove shift collar and intermediate axle
shaft.
(5) Remove the inner axle shaft seal from the shift
motor housing (Fig. 13).
(6) Remove the intermediate axle shaft bearing
(Fig. 14).
ASSEMBLY/INSTALLATION
(1) Position the bearing on installation tool. Seat
the bearing in the housing bore (Fig. 15).
(2) Clean the inside perimeter of the axle shaft
tube with fine crocus cloth.
(3) Apply a light film of oil to the inside lip of the
new axle shaft seal.
(4) Install the inner axle seal (Fig. 16, 17).
The axle shaft seal primary installation tool
6228-1 will only force the seal partially into the
Fig. 11 Shift Motor Housing and Shift Collar
Fig. 12 Vacuum Shift Motor ComponentsFig. 13 Axle Shaft Inner Seal Removal
JFRONT SUSPENSION AND AXLE 2 - 31

CAUTION: Overfilling the differential can result in
lubricant foaming and overheating.
Trac-Lok Differentials; A container of Trac-Lok lu-
bricant (friction modifier) should be added after re-
pair service or a lubricant change.
(9) Install the fill hole plug and lower the vehicle.
LIMITED SLIP DIFFERENTIAL vehicles should
be road tested by making 10 to 12 slow figure-eight
turns. This maneuver will pump the lubricant
through the clutch discs to eliminate a possible chat-
ter noise complaint.
DRIVE AXLE ASSEMBLY REPLACEMENTÐXJ
VEHICLES
REMOVAL
(1) Raise the vehicle and position support stands
under the frame rails slightly in front the springs.
(2) Remove the rear wheels.
(3) Mark the drive shaft yoke and axle pinion yoke
for alignment reference. Disconnect the drive shaft
from the axle.
(4) Disconnect the axle vent hose.
(5) Disconnect the parking brake cables at the
equalizer or backing plate.
(6) Disconnect the shock absorbers from the axle
brackets.
(7) Disconnect the brake hose at the axle junction
block.Do not disconnect the wheel cylinder tub-
ing fittings.
(8) If equipped, disconnect ABS wiring connections
at the axle.(9) Support the axle with a hydraulic jack under
the differential.
(10) Remove the spring U-bolts from the plate
brackets.
(11) Lower the jack enough to remove the axle.
INSTALLATION
CAUTION: Suspension components with rubber
bushings should be tightened with the vehicle at
normal height. It is important to have the springs
supporting the weight of the vehicle when the fas-
teners are torqued. If springs are not at their normal
ride position, vehicle ride comfort could be affected
and premature bushing wear may occur. Rubber
bushings must never be lubricated.
(1) Support the axle on a hydraulic jack under the
differential. Position the axle under the vehicle.
(2) Raise the axle and align the spring center bolts
with the locating holes in the axle pads and plate
brackets.
(3) Install the spring U-bolts through the plate
brackets and tighten to 70 Nzm (52 ft. lbs.) torque.
(4) Install ABS wiring connections (if equipped) at
the axle.
(5) Connect the brake hose at the axle junction
block.
(6) Install the shock absorbers to the axle brackets
and tighten to 62 Nzm (46 ft. lbs.) torque.
(7) Connect the parking brake cables at the equal-
izer or backing plate.
(8) Connect the vent hose to the tube fitting.
(9) Align the reference marks and connect the
drive shaft to the axle yoke. Tighten the U-joint
clamp bolts to 19 Nzm (14 ft. lbs.) torque.
(10) Check differential lubricant and add if neces-
sary.
(11) Install the wheel and tire.
(12) Bleed the brakes.
(13) Remove the supports and lower the vehicle.
DRIVE AXLE ASSEMBLY REPLACEMENTÐYJ
VEHICLES
REMOVAL
(1) Raise the vehicle and position support stands
under the frame rails slightly in front the springs.
(2) Remove the rear wheels.
(3) Mark the drive shaft yoke and axle pinion yoke
for alignment reference. Disconnect the drive shaft
from the axle.
(4) Disconnect the axle vent hose.
(5) Disconnect the parking brake cables at the
equalizer or backing plate.
(6) Disconnect the shock absorbers from the plate
brackets.
Fig. 1 Typical Housing Cover With Sealant
3 - 14 REAR SUSPENSION AND AXLESJ

LUBRICANT SPECIFICATIONS
Multi-purpose, hypoid gear lubricant should be
used in the 8 1/4 inch axle. The lubricant should
have MIL-L-2105C and API GL 5 quality specifica-
tions. MOPARtHypoid Gear Lubricant conforms to
both of these specifications.
²The factory installed lubricant for the 8 1/4 inch
rear axle is SAE 80W 90 gear lubricant.
²The factory installed lubricant quantity is 6762
fluid oz.
CAUTION: Overfilling the differential can result in
lubricant foaming and overheating.
Refer to Group 0, Lubrication and Maintenance for
additional information.
CAUTION: If axle is submerged in water, lubricant
must be replaced immediately to avoid possible
premature axle failure.
DRIVE AXLE ASSEMBLY REPLACEMENTÐXJ
VEHICLES
REMOVAL
(1) Raise the vehicle. Position support stands un-
der the frame rails slightly in front the springs.
(2) Remove the rear wheels.
(3) Mark the drive shaft yoke and axle pinion yoke
for alignment reference. Disconnect the drive shaft
from the axle.
(4) Disconnect the axle vent hose.
(5) Disconnect the parking brake cables at the
equalizer or backing plate.
(6) Disconnect the shock absorbers from the axle
brackets.
(7) Disconnect the brake hose at the axle junction
block.Do not disconnect the wheel cylinder tub-
ing fittings.
(8) If equipped, disconnect ABS wiring connections
at the axle.
(9) Support the axle with a hydraulic jack under
the differential.
(10) Remove the spring U-bolts from the plate
brackets.
(11) Lower the jack enough to remove the axle.
INSTALLATION
CAUTION: Suspension components with rubber
bushings should be tightened with the vehicle at
normal height. It is important to have the springs
supporting the weight of the vehicle when the fas-
teners are torqued. If springs are not at their normal
ride position, vehicle ride comfort could be affected
and premature bushing wear may occur. Rubber
bushings must never be lubricated.(1) Support the axle on a hydraulic jack under the
differential. Position the axle under the vehicle.
(2) Raise the axle and align the spring center bolts
with the locating holes in the axle pads and plate
brackets.
(3) Install the spring U-bolts through the plate
brackets and tighten to 70 Nzm (52 ft. lbs.) torque.
(4) Install ABS wiring connections (if equipped) at
the axle.
(5) Connect the brake hose at the axle junction
block.
(6) Install the shock absorbers to the axle brackets
and tighten to 62 Nzm (46 ft. lbs.) torque.
(7) Connect the parking brake cables at the equal-
izer or backing plate.
(8) Connect the vent hose to the tube fitting.
(9) Align the reference marks and connect the
drive shaft to the axle yoke. Tighten the U-joint
clamp bolts to 19 Nzm (14 ft. lbs.) torque.
(10) Check differential lubricant and add if neces-
sary.
(11) Install the wheel and tire.
(12) Bleed the brakes.
(13) Remove the supports and lower the vehicle.
LUBRICANT CHANGE
The gear lubricant will drain quicker if the vehicle
has been recently driven.
(1) Raise and support the vehicle.
(2) Remove the lubricant fill hole plug from the dif-
ferential housing cover.
(3) Remove the differential housing cover and
drain the lubricant from the housing.
(4) Clean the housing cavity with a flushing oil,
light engine oil or lint free cloth.Do not use water,
steam, kerosene or gasoline for cleaning.
(5) Remove the sealant from the housing and cover
surfaces. Use solvent to clean the mating surfaces.
(6) Apply a bead of MOPARtSilicone Rubber Seal-
ant to the housing cover (Fig. 2). Allow the sealant to
cure for a few minutes.
Install the housing cover within 5 minutes after
applying the sealant. If not installed the sealant
must be removed and another bead applied.
(7) Install the cover and any identification tag.
Tighten the cover bolts in a criss-cross pattern to 47
Nzm (35 ft. lbs.) torque.
(8) Refill the differential with Mopar Hypoid Gear
Lubricant 13 mm (1/2 in.) below the fill plug hole.
With Trac-Lok differentials, add a container of Mopar
Hypoid Gear Lubricant Additive.
CAUTION: Overfilling the differential can result in
lubricant foaming and overheating.
(9) Install the fill hole plug and lower the vehicle.
JREAR SUSPENSION AND AXLES 3 - 31

temperature, coolant is allowed to flow to the radia-
tor. This provides quick engine warmup and overall
temperature control.
An arrow plus the wordUPis stamped on the
front flange next to the air bleed. The wordsTO
RADare stamped on one arm of the thermostat.
They indicate the proper installed position.
The same thermostat is used for winter and sum-
mer seasons. An engine should not be operated with-
out a thermostat, except for servicing or testing.
Operating without a thermostat causes other prob-
lems. These are: longer engine warmup time, unreli-
able warmup performance, increased exhaust
emissions and crankcase condensation. This conden-
sation can result in sludge formation.
CAUTION: Do not operate an engine without a ther-
mostat, except for servicing or testing.
ON-BOARD DIAGNOSTICS
XJ and YJ models are equipped with On-Board Di-
agnostics for certain cooling system components. Re-
fer to On-Board Diagnostics (OBD) in the Diagnosis
section of this group for additional information. If the
powertrain control module (PCM) detects low engine
coolant temperature, it will record a Diagnostic Trou-
ble Code (DTC) in the PCM memory. The DTC num-
ber for low coolant temperature is 17. Do not change
a thermostat for lack of heat as indicated by the in-
strument panel gauge or heater performance unless a
DTC number 17 is present. Refer to the Diagnosis
section of this group for other probable causes. For
other DTC numbers, refer to On-Board Diagnostics
in the General Diagnosis section of Group 14, Fuel
Systems.
The DTC can also be accessed through the DRB
scan tool. Refer to the appropriate Powertrain Diag-
nostic Procedures manual for diagnostic information
and operation of the DRB scan tool.
REMOVAL
WARNING: DO NOT LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND PRES-
SURIZED. SERIOUS BURNS FROM THE COOLANT
CAN OCCUR.
DO NOT WASTE reusable coolant. If the solution
is clean, drain the coolant into a clean container for
reuse.
(1) Drain the coolant from the radiator until the
level is below the thermostat housing.
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (FIG. 15). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS. AL-
WAYS WEAR SAFETY GLASSES WHEN SERVICING
CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 16). If re-
placement is necessary, use only an original equip-
ment clamp with matching number or letter.
(2) Remove radiator upper hose and heater hose at
thermostat housing.
(3) Disconnect wiring connector at engine coolant
temperature sensor.
(4) Remove thermostat housing mounting bolts,
thermostat housing, gasket and thermostat (Fig. 17).
Discard old gasket.
(5) Clean the gasket mating surfaces.
Fig. 13 XJ Models with 4.0L 6-Cylinder EngineÐ
Without A/C
Fig. 14 XJ Models With 4.0L 6-Cylinder EngineÐ
With A/C
7 - 18 COOLING SYSTEM SERVICE PROCEDURESJ

(4) For access to radiator draincock, remove radia-
tor grille mounting screws and remove grill. Refer to
Group 23, Body for procedures.
(5) Attach one end of a 24 inch long X 1/4 inch ID
hose to the radiator draincock. Put the other end into
a clean container. Open draincock and drain radiator.
(6) If equipped, disconnect auxiliary electric cooling
fan electrical connector (Fig. 31).
(7) If equipped, remove two electric cooling fan
mounting bolts. Lift cooling fan straight up until
alignment tabs at the bottom are clear of slots in
bracket at bottom of radiator (Fig. 32).
(8) Remove the two mechanical (non-electrical) fan
shroud mounting bolts. Lift shroud straight up until
alignment tabs at the bottom are clear of slots in
bracket at bottom of radiator (Fig. 32). Place shroud
over mechanical fan.
(9) If equipped, disconnect and plug automatic
transmission fluid cooler lines. Refer to Group 21,
Transmissions for procedures. If equipped with re-
mote transmission cooler, remove line to cooler from
bracket at bottom of radiator.
(10) Disconnect radiator upper and lower hoses
clamps (Figs. 27 and 28). Disconnect radiator upper
and lower hoses.
(11) Mark the position of the hood latch striker on
the radiator crossmember and remove hood latch
striker.(12) Remove two radiator upper crossmember-to-
isolator nuts (Fig. 32).
Fig. 31 Auxiliary Electric Cooling Fan Wiring
ConnectorÐTypical
Fig. 32 Auxiliary Electric Cooling Fan and Fan ShroudÐTypical
JCOOLING SYSTEM SERVICE PROCEDURES 7 - 29

ELECTRICAL
GROUP INDEX
Group Group
AUDIO SYSTEMS........................ 8F
BATTERY/STARTER/GENERATOR SERVICE.... 8B
BATTERY/STARTING/CHARGING SYSTEMS
DIAGNOSTICS......................... 8A
CHIME/BUZZER WARNING SYSTEMS........ 8U
HORNS................................ 8G
IGNITION SYSTEMS...................... 8D
INSTRUMENT PANEL AND GAUGES......... 8E
LAMPS................................ 8L
OVERHEAD CONSOLE.................... 8C
POWER LOCKS.......................... 8P
POWER MIRRORS....................... 8TPOWER SEATS.......................... 8R
POWER WINDOWS....................... 8S
REAR WINDOW DEFOGGER............... 8N
RESTRAINT SYSTEMS................... 8M
TURN SIGNAL AND HAZARD WARNING
SYSTEMS............................. 8J
VEHICLE SPEED CONTROL SYSTEM......... 8H
WIPER AND WASHER SYSTEMS............ 8K
XJ WIRING DIAGRAMS-LEFT HAND DRIVE . . . 8W
XJ WIRING DIAGRAMS-RIGHT HAND DRIVE . 8W
YJ WIRING DIAGRAMS.................. 8W
BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS
CONTENTS
page page
BATTERY............................... 2
CHARGING SYSTEM..................... 17
IGNITION-OFF DRAW.................... 10SPECIFICATIONS........................ 23
STARTING SYSTEM...................... 11
USING ON-BOARD DIAGNOSTIC SYSTEM.... 22
GENERAL INFORMATION
The battery, starting, and charging systems operate
with one another; therefore, they must be tested as a
complete system. In order for the vehicle to start and
charge properly, all of the components involved in
these systems must perform within specifications.
Group 8A covers battery, starting (Fig. 1) and
charging (Fig. 2) system diagnostic procedures. These
procedures include the most basic conventional diag-
nostic methods, to On-Board Diagnostics (OBD) builtinto the Powertrain Control Module (PCM). Use of an
induction milliamp ammeter, volt/ohmmeter, battery
charger, carbon pile rheostat (load tester), and 12-
volt test lamp will be required.
All OBD-sensed systems are monitored by the
PCM. Each monitored circuit is assigned a Diagnos-
tic Trouble Code (DTC). The PCM will store a DTC in
electronic memory for any failure it detects. See Us-
ing On-Board Diagnostic System in this group for
more information.
JELECTRICAL 8A - 1

IGNITION-OFF DRAW
GENERAL INFORMATION
Ignition-Off Draw (IOD) refers to power being
drained from the battery with the ignition switch
turned OFF. A normal vehicle electrical system will
draw from 5 to 20 milliamps (0.005 - 0.020 amps).
This is with the ignition switch in the OFF position,
and all non-ignition controlled circuits in proper
working order. The 20 milliamps are needed to sup-
ply PCM memory, digital clock memory, and electron-
ically-tuned radio memory.
A vehicle that has not been operated for approxi-
mately 20 days, may discharge the battery to an in-
adequate level. When a vehicle will not be used for
20 days or more (stored), remove the IOD fuse in the
Power Distribution Center (PDC). This will reduce
battery discharging.
Excessive battery drain can be caused by:
²electrical items left on
²faulty or improperly adjusted switches
²internally shorted generator
²intermittent shorts in the wiring.
If the IOD is over 20 milliamps, the problem must
be found and corrected before replacing a battery. In
most cases, the battery can be charged and returned
to service.
DIAGNOSIS
Testing for high-amperage IOD must be per-
formed first to prevent damage to most milli-
amp meters.
(1) Verify that all electrical accessories are off.
Turn off all lamps, remove ignition key, and close all
doors. If the vehicle is equipped with illuminated en-
try or electronically-tuned radio, allow the systems to
automatically shut off (time out). This may take up
to 3 minutes.
(2) Determine that the underhood lamp is operat-
ing properly, then disconnect or remove bulb.
(3) Disconnect negative cable from battery.
(4) Connect a typical 12-volt test lamp (low-watt-
age bulb) between the negative cable clamp and the
battery negative terminal. Make sure that the doors
remain closed so that illuminated entry is not acti-
vated.The test lamp may light brightly for up to 3 min-
utes, or may not light at all, depending upon the ve-
hicle's electrical equipment. The term brightly, as
used throughout the following tests, implies the
brightness of the test lamp will be the same as if it
were connected across the battery.
The test lamp must be securely clamped to the neg-
ative cable clamp and battery negative terminal. If
the test lamp becomes disconnected during any part
of the IOD test, the electronic timer function will be
activated and all tests must be repeated.
(5) After 3 minutes the test lamp should turn off
or be dimly lit, depending upon the vehicle's electri-
cal equipment. If the test lamp remains brightly lit,
do not disconnect it. Remove each fuse or circuit
breaker (refer to Group 8W - Wiring Diagrams) until
test lamp is either off or dimly lit. This will isolate
each circuit and identify the source of the high-am-
perage draw.
If the test lamp is still brightly lit after disconnect-
ing each fuse and circuit breaker, disconnect the wir-
ing harness from the generator. If test lamp now
turns off or is dimly lit, see Charging System in this
group to diagnose faulty generator. Do not disconnect
the test lamp.
After high-amperage IOD has been corrected, low-
amperage IOD may be checked. It is now safe to in-
stall a milliamp meter to check for low- amperage
IOD.
(6) With test lamp still connected securely, clamp a
milliamp meter between battery negative terminal
and negative cable clamp.
Do not open any doors or turn on any electri-
cal accessories with the test lamp disconnected
or the milliamp meter may be damaged.
(7) Disconnect test lamp. Observe milliamp meter.
The current draw should not exceed 0.020 amp. If
draw exceeds 20 milliamps, isolate each circuit by re-
moving circuit breakers and fuses. The milliamp
meter reading will drop when the source of the draw
is disconnected. Repair this circuit as necessary,
whether a wiring short, incorrect switch adjustment
or a component failure is found.
8A - 10 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICSJ

STARTING SYSTEM
GENERAL INFORMATION
The starting system (Fig. 1) consists of:
²ignition switch
²starter relay
²park/neutral position switch (automatic transmis-
sion)
²wiring harness and connections
²battery
²starter with an integral solenoid.
Following is a general description of the major
starting system components. Refer to Group 8W -
Wiring Diagrams for complete circuit descriptions
and diagrams.
These components form 2 separate circuits. A high-
amperage feed circuit that feeds the starter up to
300+ amps, and a low-amperage control circuit that
operates on less than 20 amps.
Battery voltage is supplied through the low-amper-
age control circuit to the coil battery terminal of the
starter relay when the ignition switch is turned to
the START position.
If the vehicle is equipped with an automatic trans-
mission, the park/neutral position switch provides a
ground path to the starter relay coil ground terminal.
This switch provides ground only with the transmis-
sion in NEUTRAL or PARK. If the vehicle is
equipped with a manual transmission, the starter re-
lay coil ground terminal is always grounded.
With the starter relay coil now energized, the nor-
mally open relay contacts close. The relay contacts
connect the relay common feed terminal to the relay
normally open terminal. The closed relay contacts en-
ergize the starter solenoid coil windings.
The energized solenoid coils pull-in and hold-in the
solenoid plunger. The solenoid plunger pulls the shiftlever in the starter. This engages the starter overrun-
ning clutch and pinion gear with the flywheel/drive
plate ring gear.
As the solenoid plunger reaches the end of its
travel, the solenoid contact disc completes the high-
amperage starter feed circuit. Current now flows be-
tween the solenoid battery terminal and the starter
motor, energizing the starter.
Once the engine starts, the overrunning clutch pro-
tects the starter from damage by allowing the starter
pinion gear to spin faster than the pinion shaft.
When the driver releases the ignition switch to the
ON position the starter relay coil is de-energized.
This causes the relay contacts to open. When the re-
lay contacts open, the starter solenoid coil is de-ener-
gized.
When the solenoid coil is de-energized, the solenoid
plunger return spring returns the plunger to its re-
laxed position. This causes the contact disc to open
the starter feed circuit, and the shift lever to disen-
gage the overrunning clutch and pinion gear from the
ring gear.
The starter motor and solenoid are serviced only as
a complete assembly. If either component fails, the
entire assembly must be replaced.
DIAGNOSIS
Before removing any unit from the starting system
for repair, perform the following inspections:
INSPECTION
BATTERY INSPECTION
To determine condition of the battery, see Battery
in this group.
WIRING INSPECTION
Inspect wiring for damage. Inspect all connections
at:
²starter solenoid
²park/neutral position switch (automatic transmis-
sion)
²ignition switch
²starter relay
²battery (including all ground connections).
Clean, tighten and repair all connections as re-
quired.
SOLENOID, RELAY AND SWITCH INSPECTIONS
Inspect the solenoid, relay and ignition switch to
determine their condition. Also, if equipped with au-
tomatic transmission, inspect condition of the park/
neutral position switch. Testing information can be
found in the following pages.
Fig. 1 Starting System Components (Typical)
JBATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 11

(4) Connect voltmeter to measure between the bat-
tery negative post and a good clean ground on the
engine block (Fig. 5). Rotate and hold ignition switch
in the START position. Observe voltmeter. If voltage
reads above 0.2 volt, correct poor contact at battery
negative cable attaching point. Repeat test. If read-
ing is still above 0.2 volt, replace battery negative ca-
ble.
(5) Connect positive lead of voltmeter to starter
housing. Connect negative lead of voltmeter to bat-
tery negative terminal (Fig. 6). Rotate and hold igni-
tion switch in the START position. Observe
voltmeter. If voltage reads above 0.2 volt, correct poor
starter to engine ground.
If resistance tests detect no feed circuit problems,
remove the starter and see Solenoid Test in this
group.
CONTROL CIRCUIT TESTS
The starter control circuit consists of:
²starter solenoid
²starter relay
²ignition switch
²park/neutral position switch (automatic transmis-
sion)²wiring harness and connections.
Test procedures for these components are as fol-
lows, and should be followed in the order described.
CAUTION: Before performing any test, unplug Auto
Shut-Down (ASD) relay from Power Distribution
Center (PDC) to prevent engine from starting.
SOLENOID TEST
Refer to Group 8B - Battery/Starter/Generator Ser-
vice for starter removal procedures.
(1) Disconnect solenoid field coil wire from field
coil terminal.
(2) Check for continuity between solenoid terminal
and field coil terminal with a continuity tester. There
should be continuity (Fig. 7).
(3) Check for continuity between solenoid terminal
and solenoid case. There should be continuity (Fig.
8).
(4) If there is continuity, solenoid is good. If there
is no continuity in either test, solenoid has an open
circuit and is faulty. Replace starter assembly.
(5) Connect solenoid field coil wire to field coil ter-
minal.
(6) Install starter as described in Group 8B - Bat-
tery/Starter/Generator Service.
RELAY TEST
The starter relay is in the Power Distribution Cen-
ter (PDC)(Figs. 9 or 10). Refer to the underside of the
PDC cover for relay location.
Fig. 5 Test Ground Circuit Resistance
Fig. 6 Test Starter Ground (Typical)
Fig. 7 Continuity Test Between Solenoid Terminal
and Field Coil Terminal
Fig. 8 Continuity Test Between Solenoid Terminal
and Solenoid Case
8A - 14 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICSJ

CHARGING SYSTEM
GENERAL INFORMATION
The charging system consists of:
²generator
²voltage regulator circuitry (within PCM)
²ignition switch
²battery
²generator warning lamp or voltmeter (depending
on vehicle equipment)
²wiring harness and connections.
Following is a general description of the major
charging system components. Refer to Group 8W -
Wiring Diagrams for complete circuit descriptions
and diagrams.
The charging system is turned on and off with the
ignition switch. When the ignition switch is turned to
the ON position, battery voltage is applied to the
generator rotor through one of the two field termi-
nals to produce a magnetic field. The generator is
driven by the engine through a serpentine belt and
pulley arrangement.
As the energized rotor begins to rotate within the
generator, the spinning magnetic field induces a cur-
rent into the windings of the stator coil. Once the
generator begins producing sufficient current, it also
provides the current needed to energize the rotor.
The wye (Y) type stator winding connections de-
liver the induced AC current to 3 positive and 3 neg-
ative diodes for rectification. From the diodes,
rectified DC current is delivered to the vehicle elec-
trical system through the generator battery and
ground terminals.
The amount of DC current produced by the gener-
ator is controlled by the generator voltage regulator
(field control) circuitry, contained within the Power-
train Control Module (PCM)(Fig. 1). This circuitry is
connected in series with the second rotor field termi-
nal and ground.
Voltage is regulated by cycling the ground path to
control the strength of the rotor magnetic field. The
generator voltage regulator circuitry monitors system
line voltage and ambient temperature. It then com-
pensates and regulates generator current output ac-
cordingly.
The generator is serviced only as a complete as-
sembly. If the generator fails for any reason, the en-
tire assembly must be replaced. The generator
voltage regulator (field control) circuitry can be ser-
viced only by replacing the entire PCM.
All vehicles are equipped with On-Board Diagnos-
tics (OBD). All OBD-sensed systems, including the
generator voltage regulator (field control) circuitry,
are monitored by the PCM. Each monitored circuit is
assigned a Diagnostic Trouble Code (DTC). The PCM
will store a DTC in electronic memory for any failureit detects. See Using On-Board Diagnostic System in
this group for more information.
DIAGNOSIS
When operating normally, the indicator lamp on
models with the base instrument cluster will light
when the ignition switch is turned to the ON or
START position. After the engine starts, the indicator
lamp goes off. With the engine running, the charge
indicator lamp should light only when there is a
problem in the charging system (base cluster only).
On models with a voltmeter, when the ignition
switch is turned to the ON position, battery potential
will register on the meter. During engine cranking a
lower voltage will appear on the meter. With the en-
gine running, a voltage reading higher than the first
reading (ignition in ON) should register.
The following procedures may be used to diagnose
the charging system if:
²the indicator or voltmeter do not operate properly
²an undercharged or overcharged battery condition
occurs.
Remember that an undercharged battery is often
caused by:
Fig. 1 Charging System Components (Typical)
JBATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 17