1994 JEEP CHEROKEE Starter

GENERATOR TEST PROCEDURES ON VEHICLE
INDEX
page page
Diagnostic Procedures..................... 15
General Information....................... 14Operational Check with Battery Indicator
(Base Cluster Only)..................... 14
Operational Check with Voltmeter............ 15
GENERAL INFORMATION
The generator is belt-driven by the engine. All en-
gines use serpentine drive.
The amount of DC current produced by the gener-
ator is controlled by the Powertrain Control Module
(PCM) (Fig. 1).
All vehicles are equipped with On-Board Diagnos-
tics (OBD). All OBD sensing systems are monitored
by the PCM. The PCM will store in electronic mem-
ory any detectable failure within the monitored cir-
cuits. Refer to Using On-Board Diagnostic System in
this group for more information.
OPERATIONAL CHECK WITH BATTERY INDICATOR
(BASE CLUSTER ONLY)
When operating normally, the indicator bulb will
come on when the ignition switch is turned to the
ON or START position. After the engine starts, the
indicator bulb goes off. With the engine running, the
charge indicator should come on only when there is a
problem in the charging system (base cluster only).
Fig. 10 Starter Motor Shimming
Fig. 1 Charging System Components (Typical)
8A - 14 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICSJ

OPERATIONAL CHECK WITH VOLTMETER
When the ignition switch is turned to the ON po-
sition, battery potential will register on the voltme-
ter. During engine cranking a lower voltage will
appear on the meter. With the engine running, a
voltage reading higher than the first reading (igni-
tion in ON) should register.
DIAGNOSTIC PROCEDURES
If the indicator operates abnormally, or if an un-
dercharged or overcharged battery condition occurs,
the following procedures may be used to diagnose the
charging system.
Remember that an undercharged battery is often
caused by:
²accessories being left on overnight
²or by a defective switch which allows a bulb, such
as a liftgate or glove box light, to stay on (refer to
Ignition Off Draw Diagnosis).
VISUAL INSPECTION
²Inspect condition of battery cable terminals, bat-
tery posts, connections at engine block, starter motor
solenoid and relay. They should be clean and tight.
Repair as required.
²Inspect all fuses in the fuse block for tightness in
receptacles. They should be properly installed and
tight. Repair or replace as required.²Inspect the electrolyte level in the battery and add
water if necessary.
²Inspect generator mounting bolts for tightness. Re-
place or torque bolt as required. Refer to Torque
Specifications in Battery/Starter/Generator Service.
²Inspect generator drive belt condition and tension.
Tension or replace belt as required. Refer to Belt
Tension Specifications in Battery/Starter/Generator
Service.
²Inspect connection at generator B+ output. It
should be clean and tight. Repair as required.
GENERATOR OUTPUT WIRE RESISTANCE
TEST
Generator output wire resistance test will show
amount of voltage drop across generator output wire
between generator battery terminal and battery pos-
itive post.
PREPARATION
(1) Before starting test make sure vehicle has a
fully charged battery. Test and procedures on how to
check for a fully charged battery are shown in Bat-
tery Test Procedures.
(2) Turn OFF ignition switch.
(3) Disconnect negative cable from battery.
(4) Disconnect generator output wire from genera-
tor output battery terminal.
Fig. 2 Generator Output Wire Resistance Test (Typical)
JBATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 15

(5) Connect a 0-150 ampere scale D.C. ammeter in
series between generator battery terminal and dis-
connected generator output wire (Fig. 2). Connect
positive lead to generator battery terminal and neg-
ative lead to disconnected generator output wire.
(6) Connect positive lead of a test voltmeter (range
0-18 volts minimum) to disconnected generator out-
put wire. Connect negative lead of test voltmeter to
battery positive cable at positive post.
(7) Connect one end of a jumper wire to ground
and with other end probe green K20 lead wire at
back of generator (Fig. 2). This will generate a DTC.
CAUTION: Do not connect green/orange A142 lead
of wiring to ground. Refer to Group 8W - Wiring Di-
agrams for more information.
(8) Connect an engine tachometer and connect neg-
ative cable to battery.
(9) Connect a variable carbon pile rheostat be-
tween battery terminals. Be sure carbon pile is in
OPEN or OFF position before connecting leads. See
Load Testing in Battery Test Procedures for instruc-
tions.
TEST
(1) Start engine. Immediately after starting, re-
duce engine speed to idle.
(2) Adjust engine speed and carbon pile to main-
tain 20 amperes flowing in circuit. Observe voltmeter
reading. Voltmeter reading should not exceed 0.5
volts.
RESULTS
If a higher voltage drop is indicated, inspect, clean
and tighten all connections between generator bat-
tery terminal and battery positive post. A voltage
drop test may be performed at each connection to lo-
cate connection with excessive resistance. If resis-
tance tested satisfactorily, reduce engine speed, turn
OFF carbon pile and turn OFF ignition switch.
(1) Disconnect negative cable from battery.
(2) Remove test ammeter, voltmeter, carbon pile,
and tachometer.
(3) Remove jumper wire.
(4) Connect generator output wire to generator
battery terminal. Tighten to 5 to 6 NIm (45 to 75 in.
lbs.).
(5) Connect negative cable to battery.
(6) Use DRB scan tool to erase DTC.
GENERATOR OUTPUT TEST
Generator output test determines whether genera-
tor can deliver its rated current output.PREPARATION
(1) Before starting any tests make sure vehicle has
a fully charged battery. Test and procedures on how
to check for a fully charged battery are shown in
Battery Test Procedures.
(2) Disconnect negative cable from battery.
(3) Disconnect generator output wire at the gener-
ator battery terminal.
(4) Connect a 0-150 ampere scale D.C. ammeter in
series between generator battery terminal and dis-
connected generator output wire (Fig. 3). Connect
positive lead to generator battery terminal and neg-
ative lead to disconnected generator output wire.
(5) Connect positive lead of a test voltmeter (range
0-18 volts minimum) to generator battery terminal.
(6) Connect negative lead of test voltmeter to a
good ground.
(7) Connect an engine tachometer and connect bat-
tery negative cable.
(8) Connect a variable carbon pile rheostat be-
tween battery terminals. Be sure carbon pile is in
OPEN or OFF position before connecting leads. See
Load Testing in Battery Test Procedures.
(9) Connect one end of a jumper wire to ground
and with other end probe green K20 lead wire at
back of generator (Fig. 3). This will generate a DTC.
CAUTION: Do not connect green/orange A142 lead
of wiring to ground. Refer to Group 8W - Wiring Di-
agrams for more information.
TEST
(1) Start engine. Immediately after starting reduce
engine speed to idle.
(2) Adjust carbon pile and engine speed in incre-
ments until a speed of 1250 rpm and voltmeter read-
ing of 15 volts is obtained.
CAUTION: Do not allow voltage meter to read above
16 volts.
(3) The ammeter reading must be within limits
shown for that size of generator being tested. See
Generator Specifications in Battery/Starter/Genera-
tor Service.
RESULTS
(1) If reading is less than specified and generator
output wire resistance is not excessive, generator
should be replaced. Refer to Group 8B - Battery/
Starter/Generator Service.
(2) After current output test is completed reduce
engine speed, turn OFF carbon pile and turn OFF ig-
nition switch.
(3) Disconnect negative cable from battery.
(4) Remove test ammeter, voltmeter, tachometer
and carbon pile.
8A - 16 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICSJ

BATTERY/STARTER/GENERATOR SERVICE
CONTENTS
page page
BATTERY SERVICE PROCEDURES.......... 1
ENGINE STARTER MOTOR SERVICE
PROCEDURES......................... 4GENERATOR SERVICE PROCEDURES........ 7
SPECIFICATIONS....................... 10
BATTERY SERVICE PROCEDURES
GENERAL INFORMATION
This section covers battery removal and installa-
tion procedures only. For diagnostic procedures, refer
to Group 8A - Battery/Starting/Charging Systems Di-
agnostics.
BATTERY MAINTENANCE
(1) Inspect cable terminals for corrosion and dam-
age. Remove the corrosion using a wire brush, or
post and terminal cleaner, and a sodium bicarbonate/
water solution. Replace cables that have damaged or
deformed terminals.
Be sure filler caps or vents are installed when
washing battery to prevent solution from enter-
ing battery.
(2) Clean outside of battery case if the original
battery is to be installed. Clean top cover with di-
luted ammonia or a sodium bicarbonate/water solu-
tion to remove acid film. Flush with clean water.
Ensure that cleaning solution does not enter cells.
(3) Remove corrosion from the terminals with a
wire brush or post and terminal cleaner. Inspect the
case for cracks or other damage that would result in
leakage of electrolyte.
(4) Check electrolyte level in the battery. Use a
putty knife or other suitable wide tool to pry filler
caps off low maintenance battery (Fig. 1). Do not use
a screwdriver. Add distilled water to each cell until
the liquid reaches the bottom of the vent well. DO
NOT OVERFILL.
(5) Operate the engine immediately after adding
water (particularly in cold weather) to assure proper
mixing of the water and acid.
BATTERY REPLACEMENTÐLEFT HAND DRIVE
REMOVAL
(1) Make sure ignition switch is in OFF position
and all electrical accessories are OFF.
(2) Loosen the cable terminal clamps.
(3) If necessary, use a puller to remove cable ter-
minal clamps. Remove negative cable terminal clamp
first.WARNING: WEAR A SUITABLE PAIR OF RUBBER
GLOVES (NOT THE HOUSEHOLD TYPE) WHEN RE-
MOVING A BATTERY BY HAND. SAFETY GLASSES
ALSO SHOULD BE WORN. IF THE BATTERY IS
CRACKED OR LEAKING, THE ELECTROLYTE CAN
BURN THE SKIN AND EYES.
(4) Remove battery holddown, and remove battery
from vehicle (Figs. 2 and 3).
(5) Inspect battery tray and holddowns for corro-
sion. Remove corrosion using a wire brush and a so-
dium bicarbonate/water solution. Paint any exposed
bare metal. Replace damaged components (Figs. 4
and 5).
INSTALLATION
(1) Refer to Specifications to determine if battery
has correct classification and rating for the vehicle.
(2) Use a hydrometer to test the battery electro-
lyte. Charge battery if necessary.
(3) Position battery in tray. Ensure that positive
and negative terminals (posts) are correctly located.
The cables must reach their terminals (posts) with-
out stretching (Figs. 2 and 3).
Fig. 1 Removing Filler Cap
JBATTERY/STARTER/GENERATOR SERVICE 8B - 1

(4) Ensure that tang at battery base is positioned
in tray properly before tightening holddown.
CAUTION: It is imperative that the cables are con-
nected to the battery positive-to-positive and nega-
tive-to-negative. Reverse polarity will damage the
generator diodes and radio(s).
(5) Place felt washer on positive battery terminal.
(6) Connect positive cable first. Then connect neg-
ative cable. Tighten both cable terminal bolts to 8.5
Nzm (75 in. lbs.).(7) Apply a thin coating of petroleum jelly or chas-
sis grease to cable terminals and battery posts.
(8) Inspect negative cable connections on engine
and vehicle body for condition, security and electrical
continuity.
BATTERY REPLACEMENTÐRIGHT HAND DRIVE
REMOVAL
(1) Make sure ignition switch is in OFF position
and all electrical accessories are OFF.
Fig. 2 Battery HolddownÐXJ
Fig. 3 Battery HolddownÐYJ
Fig. 4 Battery TrayÐXJ
Fig. 5 Battery TrayÐYJ
8B - 2 BATTERY/STARTER/GENERATOR SERVICEJ

(2) Remove bolt and negative cable from battery
(Fig. 6).
(3) Remove bolt and positive cable from battery.
WARNING: WEAR A SUITABLE PAIR OF RUBBER
GLOVES (NOT THE HOUSEHOLD TYPE) WHEN RE-
MOVING A BATTERY BY HAND. SAFETY GLASSES
ALSO SHOULD BE WORN. IF THE BATTERY ISCRACKED OR LEAKING, THE ELECTROLYTE CAN
BURN THE SKIN AND EYES.
(4) Remove battery holddown and battery from ve-
hicle.
(5) Inspect battery tray and holddowns for corro-
sion. Remove corrosion using a wire brush and a so-
dium bicarbonate/water solution. Paint any exposed
bare metal. Replace damaged components.
INSTALLATION
(1) Refer to Specifications to determine if battery
has correct classification and rating for the vehicle.
(2) Use a hydrometer to test the battery electro-
lyte. Charge battery if necessary.
(3) Position battery in tray. Ensure that positive
and negative terminals are correctly located. The ca-
bles must reach their terminals without stretching
(Fig. 6).
(4) Ensure that battery base is positioned in tray
properly before tightening holddown.
CAUTION: It is imperative that the cables are con-
nected to the battery positive-to-positive and nega-
tive-to-negative. Reverse polarity will damage the
generator diodes and radio(s).
(5) Connect positive cable first. Then connect neg-
ative cable. Tighten both cable terminal bolts to
10-20 Nzm (90-178 in. lbs.).
(6) Inspect negative cable connections on engine
and vehicle body for condition, security and electrical
continuity.
Fig. 6 Battery Cable Attachment
JBATTERY/STARTER/GENERATOR SERVICE 8B - 3

ENGINE STARTER MOTOR SERVICE PROCEDURES
INDEX
page page
2.5L Starter General Information.............. 4
2.5L Starter Motor Removal/Installation......... 5
4.0L Starter General Information.............. 6
4.0L Starter Motor Removal/Installation......... 6General Information........................ 4
Park/Neutral Position Switch................. 6
Starter Relay Replacement.................. 4
GENERAL INFORMATION
This section will cover the starting system compo-
nent service procedures only. For diagnostic proce-
dures, refer to Group 8A - Battery/Starting/Charging
Systems Diagnostics.
Starting system components: battery, starter mo-
tor, starter relay, starter solenoid, ignition switch,
connecting wires and battery cables. A park/neutral
position switch is used with automatic transmissions.
STARTER RELAY REPLACEMENT
The starter relay is located in the Power Distribu-
tion Center (Figs. 1 and 2). Refer to underside of
Power Distribution Center cover for relay location.
(1) Disconnect negative cable from battery.
(2) Replace relay.
(3) Connect negative cable to battery.
(4) Test relay operation.
2.5L STARTER GENERAL INFORMATION
The 2.5L engine starter motor incorporates several
features to create an efficient, lightweight unit.
A planetary gear system (intermediate transmis-
sion) between the electric motor and pinion shaftmakes it possible to reduce the dimensions of the
starter. This also makes it possible to obtain a higher
rotational speed to produce the same torque at the
pinion.
The permanent magnet field consists of six two-
component high strength magnets. The magnets are
aligned according to their polarity and are perma-
nently fixed in the starter frame.
The brush holder plate consists of a plastic base-
plate with four tubular brush holders.
This unit is highly sensitive to hammering, shocks
and external pressure.
CAUTION: The starter motor MUST NOT BE
CLAMPED in a vise by the starter frame. Doing so
may damage the magnets. It may be clamped by the
mounting flange ONLY.
CAUTION: Do not connect starter motor incorrectly
when tests are being performed. The magnets may
be damaged and rendered unserviceable.
²Ensure cleanliness when performing repairs.
Fig. 1 Power Distribution CenterÐXJ
Fig. 2 Power Distribution CenterÐYJ
8B - 4 BATTERY/STARTER/GENERATOR SERVICEJ

²Metal chips are attracted by the magnets and may
not be completely removed from the starter frame.
Chips in the ring gear can lead to failure of the
starter.
2.5L STARTER MOTOR REMOVAL/INSTALLATION
XJÐ2.5L ENGINE
(1) Disconnect negative cable from battery.
(2) Remove exhaust clamp from bracket (Fig. 3).
(3) Remove nut and bolt from forward end of brace
rod (automatic transmission only).
(4) Remove nut from lower end of brace rod (auto-
matic transmission only).
(5) Remove brace rod and bracket (automatic
transmission only).
(6) Remove nut, bolt and bracket from bell housing
(manual transmission only).
(7) Disconnect battery cable and solenoid feed wire
from solenoid (Fig. 4).
(8) Remove starter motor mounting bolts, starter
motor and shims.
Two shim thicknesses are available. One is
0.381 mm (0.015 in.) and the other is 1.143 mm
(0.045 in.). Refer to Group 8A for proper shim se-
lection.
(9) To install starter motor, reverse the removal
procedures and torque mounting hardware as shown.
(10) Connect negative cable to battery.
YJÐ2.5L ENGINE
(1) Disconnect negative cable from battery.
(2) Disconnect battery cable from starter motor
B+ terminal (Fig. 5).(3) Disconnect solenoid feed wire.
(4) Remove starter motor mounting bolts.
(5) Remove starter motor and shims.
Two shim thicknesses are available. One is
0.381 mm (0.015 in.) and the other is 1.143 mm
(0.045 in.). Refer to Group 8A for proper shim se-
lection.
(6) To install starter motor, reverse removal proce-
dures and torque mounting hardware as shown.
(7) Connect negative cable to battery.
Fig. 3 Exhaust Clamp and Brace RemovalÐ2.5L XJ
Fig. 4 Starter Motor Removal/InstallationÐ2.5L XJ
Fig. 5 Starter Motor Removal/InstallationÐ2.5L YJ
JBATTERY/STARTER/GENERATOR SERVICE 8B - 5