
BATTERY
CONTENTS
page page
GENERAL INFORMATION
INTRODUCTION........................ 1
SAFETY PRECAUTIONS AND WARNINGS.... 1
DESCRIPTION AND OPERATION
BATTERY IGNITION OFF DRAW (IOD)....... 2
CHARGING TIME REQUIRED.............. 2
DIAGNOSIS AND TESTING
BATTERY DISCHARGING................. 3
BATTERY IGNITION OFF DRAW............ 3
BATTERY LOAD TEST................... 5
BATTERY OPEN CIRCUIT VOLTAGE TEST.... 6SERVICE PROCEDURES
BATTERY CHARGING.................... 6
CHARGING COMPLETELY DISCHARGED
BATTERY............................ 7
VISUAL INSPECTION.................... 7
REMOVAL AND INSTALLATION
BATTERY............................. 8
BATTERY TRAY........................ 9
SPECIFICATIONS
BATTERY SPECIFICATIONS............... 9
TORQUE............................. 10
GENERAL INFORMATION
INTRODUCTION
The battery stores, stabilizes, and delivers electri-
cal current to operate various electrical systems in
the vehicle (Fig. 1). The determination of whether a
battery is good or bad is made by its ability to accept
a charge. It also must supply high-amperage current
for a long enough period to be able to start the vehi-
cle. The capability of the battery to store electrical
current comes from a chemical reaction. This reac-
tion takes place between the sulfuric acid solution
(electrolyte) and the lead +/- plates in each cell of the
battery. As the battery discharges, the plates react
with the acid from the electrolyte. When the charging
system charges the battery, the water is converted to
sulfuric acid in the battery. The concentration of acid
in the electrolyte is measured as specific gravity
using a hydrometer. The specific gravity indicates the
battery's state-of-charge.
The battery is vented to release gases that are cre-
ated when the battery is being charged and dis-
charged.
The battery top, posts, and terminals should be
cleaned when other under hood maintenance is per-
formed.
The battery top, posts, cable clamps must be
cleaned and battery must be completely charged
before diagnostic procedures are performed.
SAFETY PRECAUTIONS AND WARNINGS
WARNING:
DO NOT ALLOW JUMPER CABLE CLAMPS TO
TOUCH EACH OTHER WHEN CONNECTED TO A
BOOSTER SOURCE.
DO NOT USE OPEN FLAME NEAR BATTERY.
REMOVE METALLIC JEWELRY WORN ON
HANDS OR WRISTS TO AVOID INJURY BY ACCI-
DENTAL ARCING OF BATTERY CURRENT.
WHEN USING A HIGH OUTPUT BOOSTING
DEVICE, DO NOT ALLOW THE DISABLED VEHI-
CLE'S BATTERY TO EXCEED 16 VOLTS. PER-
SONAL INJURY OR DAMAGE TO ELECTRICAL
SYSTEM CAN RESULT.
TO PROTECT THE HANDS FROM BATTERY
ACID, A SUITABLE PAIR OF HEAVY DUTY RUB-
Fig. 1 Battery Construction
NS/GSBATTERY 8A - 1

BER GLOVES, NOT THE HOUSEHOLD TYPE,
SHOULD BE WORN WHEN REMOVING OR SER-
VICING A BATTERY. SAFETY GLASSES ALSO
SHOULD BE WORN.
DESCRIPTION AND OPERATION
BATTERY IGNITION OFF DRAW (IOD)
A completely normal vehicle will have a small
amount of current drain on the battery with the key
out of the ignition. It can range from 5 to 25 milli-
amperes after all the modules time out. If a vehicle
will not be operated for approximately a 20 days, the
IOD fuse should be pulled to eliminate the vehicle
electrical drain on the battery. The IOD fuse is
located in the Power Distribution Center (PDC).
Refer to the PDC cover for proper fuse.
CHARGING TIME REQUIRED
WARNING: NEVER EXCEED 20 AMPS WHEN
CHARGING A COLD -1ÉC (30ÉF) BATTERY. PER-
SONAL INJURY MAY RESULT.
The time required to charge a battery will vary
depending upon the following factors.
SIZE OF BATTERY
A completely discharged large heavy-duty battery
may require more recharging time than a completely
discharged small capacity battery, refer to (Fig. 2) for
charging times.
TEMPERATURE
A longer time will be needed to charge a battery at
-18ÉC (0ÉF) than at 27ÉC (80ÉF). When a fast charger
is connected to a cold battery, current accepted by
battery will be very low at first. In time, the battery
will accept a higher rate as battery temperature
warms.
CHARGER CAPACITY
A charger which can supply only five amperes will
require a much longer period of charging than a
charger that can supply 20 amperes or more.
STATE OF CHARGE
A completely discharged battery requires more
charging time than a partially charged battery. Elec-
trolyte is nearly pure water in a completely dis-
charged battery. At first, the charging current
amperage will be low. As water is converted back to
sulfuric acid inside the battery, the current amp rate
will rise. Also, the specific gravity of the electrolyte
will rise. The electrolyte should be tested with a
Hydrometer to check the specific gravity.
USING HYDROMETER
Before performing a hydrometer test, remove the
battery caps and check the electrolyte level. Add dis-
tilled water as required.
NOTE: Periodically disassemble the hydrometer
and wash components with soap and water. Inspect
the float for possible leaks. If the paper inside has
turned brown, the float is defective.
Before testing, visually inspect the battery for any
damage:
²Cracked container or cover
²Loose post
²Corrosion
and any other thing that would cause the battery
to be unserviceable. To interpret the hydrometer cor-
rectly, hold it with the top surface of the electrolyte
in the hydrometer at eye level.
Disregard the curvature of the liquid where the
surface rises against the float because of surface
cohesion (Fig. 3). Remove only enough electrolyte
from the battery to keep the float off the bottom of
the hydrometer barrel with pressure on the bulb
released. Keep the hydrometer in a vertical position
while drawing the electrolyte into the hydrometer
and observing the specific gravity. Exercise care
when inserting the tip of the hydrometer into a cell
to avoid damage to the separators. Damaged separa-
tors can cause premature battery failure.
Hydrometer floats are generally calibrated to indi-
cate the specific gravity correctly only at one fixed
temperature, 20ÉC (68ÉF). When testing the specific
gravity at any other temperature, a correction factor
is required, otherwise specific gravity readings will
not indicate the true state of charge.
The correction factor is approximately a specific
gravity value of 0.004, referred to as 4 points of spe-
cific gravity for every 5.5ÉC (10ÉF). If electrolyte tem-
perature is below 20ÉC (68ÉF) you subtract. If the
temperature is above 20ÉC (68ÉF) you add to the
Fig. 2 Battery Charging Time
8A - 2 BATTERYNS/GS
GENERAL INFORMATION (Continued)

hydrometer reading. Always correct the specific grav-
ity for temperature variation. Test the specific grav-
ity of the electrolyte in each battery cell. Refer to the
information with the Hydrometer.
Example 1:
²Hydrometer reading: 1.260
²Electrolyte temperature: -7ÉC (20ÉF)
²Subtract specific gravity: -0.019
²Correction specific gravity: 1.241
Example 2:
²Hydrometer reading: 1.225
²Electrolyte temperature: -38ÉC (100ÉF)
²Add specific gravity: +0.013
²Correction specific gravity: 1.238
A fully charged relatively new battery has a spe-
cific gravity reading of 1.285 plus 0.015 or minus
0.010.
If the specific gravity of all cells is above 1.235, but
variation between cells is more than 50 points
(0.050), it is an indication that the battery is unser-
viceable.
If the specific gravity of one or more cells is less
than 1.235, recharge the battery at a rate of approx-
imately 5 amperes. Continue charging until three
consecutive specific gravity tests, taken at one-hour
intervals, are constant.
If the cell specific gravity variation is more than 50
points (0.050) at the end of the charge period, replace
the battery.When the specific gravity of all cells is above 1.235
and variation between cells is less than 50 points
(0.050), the battery may be tested under heavy load.
DIAGNOSIS AND TESTING
BATTERY DISCHARGING
CAUSE OF BATTERY DISCHARGING
It is normal to have a small 5 to 25 milliamperes
continuous electrical draw from the battery. This
draw will take place with the ignition in the OFF
position, and the courtesy, dome, storage compart-
ments, and engine compartment lights OFF. The con-
tinuous draw is due to various electronic features or
accessories that require electrical current with the
ignition OFF to function properly. When a vehicle is
not used over an extended period of approximately 20
days the IOD fuse should be disconnected. The fuse
is located in the power distribution center. Disconnec-
tion of this fuse will reduce the level of battery dis-
charge. Refer to Battery Diagnosis and Testing Chart
and to the proper procedures.
ABNORMAL BATTERY DISCHARGING
²Corroded battery posts, cables or terminals.
²Loose or worn generator drive belt.
²Electrical loads that exceed the output of the
charging system due to equipment or accessories
installed after delivery.
²Slow driving speeds in heavy traffic conditions
or prolonged idling with high-amperage electrical
systems in use.
²Defective electrical circuit or component causing
excess Ignition Off Draw (IOD). Refer to Battery
Ignition Off Draw (IOD).
²Defective charging system.
²Defective battery.
BATTERY IGNITION OFF DRAW
High current draw on the battery with the ignition
OFF will discharge a battery. After a dead battery is
serviced the vehicle Ignition Off Draw (IOD) should
be checked. Determine if a high current draw condi-
tion exists first check the vehicle with a test lamp.
(1) Verify that all electrical accessories are OFF.
²Remove key from ignition switch
²Turn off all lights
²Liftgate and glove box door is closed
²Sun visor vanity lights are OFF
²All doors are closed
²Allow the Illuminated Entry System to time out
in approximately 30 seconds, if equipped.
(2) Disconnect battery negative cable (Fig. 4).
Fig. 3 Battery Hydrometer
NS/GSBATTERY 8A - 3
DESCRIPTION AND OPERATION (Continued)

(6) If battery passes load test, it is in good condi-
tion and further tests are not necessary. If it fails
load test, it should be replaced.
BATTERY OPEN CIRCUIT VOLTAGE TEST
An open circuit voltage no load test shows the
state of charge of a battery and whether it is ready
for a load test at 50 percent of the battery's cold
crank rating. Refer to Battery Load Test. If a battery
has open circuit voltage reading of 12.4 volts or
greater, and will not pass the load test, replace the
battery because it is defective. To test open circuit
voltage, perform the following operation.
(1) Remove both battery cables, negative cable
first. Battery top, cables and posts should be clean. If
green dot is not visible in indicator, charge the bat-
tery. Refer to Battery Charging Procedures.
(2) Connect a Volt/Ammeter/Load tester to the bat-
tery posts (Fig. 6). Rotate the load control knob of the
Carbon pile rheostat to apply a 300 amp load. Apply
this load for 15 seconds to remove the surface charge
from the battery, and return the control knob to off
(Fig. 7).(3) Allow the battery to stabilize for 2 minutes,
and then verify the open circuit voltage (Fig. 9).
(4) This voltage reading will approximate the state
of charge of the battery. It will not reveal battery
cranking capacity (Fig. 10).
SERVICE PROCEDURES
BATTERY CHARGING
WARNING: DO NOT CHARGE A BATTERY THAT
HAS EXCESSIVELY LOW ELECTROLYTE LEVEL.
BATTERY MAY SPARK INTERNALLY AND
EXPLODE. EXPLOSIVE GASES FORM OVER THE
BATTERY. DO NOT SMOKE, USE FLAME, OR CRE-
ATE SPARKS NEAR BATTERY. DO NOT ASSIST
BOOST OR CHARGE A FROZEN BATTERY. BAT-
TERY CASING MAY FRACTURE. BATTERY ACID IS
POISON, AND MAY CAUSE SEVERE BURNS. BAT-
TERIES CONTAIN SULFURIC ACID. AVOID CON-
TACT WITH SKIN, EYES, OR CLOTHING. IN THE
EVENT OF CONTACT, FLUSH WITH WATER AND
CALL PHYSICIAN IMMEDIATELY. KEEP OUT OF
REACH OF CHILDREN.
Fig. 8 Load 50% Cold Crank Rating
Load Test Temperature
Minimum VoltageTemperature
ÉF ÉC
9.6 volts 70É and
above21É and
above
9.5 volts 60É 16É
9.4 volts 50É 10É
9.3 volts 40É 4É
9.1 volts 30É -1É
8.9 volts 20É -7É
8.7 volts 10É -12É
8.5 volts 0É -18É
Fig. 9 Testing Open Circuit Voltage
Fig. 10 Battery Open Circuit Voltage
8A - 6 BATTERYNS/GS
DIAGNOSIS AND TESTING (Continued)

CAUTION: Disconnect the battery NEGATIVE cable
first (Fig. 4) before charging battery to avoid dam-
age to electrical systems. Do not exceed 16.0 volts
while charging battery. Refer to the instructions
supplied with charging equipment
A battery is considered fully charged when it will
meet all the following requirements.
²It has an open circuit voltage charge of at least
12.4 volts (Fig. 10).
²It passes the 15 second load test, refer to the
Load Test Temperature chart.
²The specific gravity reading is 1.285 plus 0.015
or minus 0.010.
Battery electrolyte will bubble inside of battery
case while being charged properly. If the electrolyte
boils violently, or is discharged from the vent holes
while charging, immediately reduce charging rate or
turn off charger. Evaluate battery condition. Battery
damage may occur if charging is excessive.
Some battery chargers are equipped with polarity
sensing devices to protect the charger or battery from
being damaged if improperly connected. If the bat-
tery state of charge is too low for the polarity sensor
to detect, the sensor must be bypassed for charger to
operate. Refer to operating instructions provided
with battery charger being used.
CAUTION: Do not overcharge Battery.
Test the battery until the specific gravity reading
is 1.285 plus 0.015 or minus 0.010.
After the battery has been charged to 12.4 volts or
greater, perform a load test to determine cranking
capacity. Refer to Battery Load Test in this Group. If
the battery passes the load test, return the battery to
use. If battery will not endure a load test, it must be
replaced. Properly clean and inspect battery hold
downs, tray, terminals, cables, posts, and top before
completing service.
CHARGING COMPLETELY DISCHARGED BATTERY
The following procedure should be used to recharge
a completely discharged battery. Unless procedure is
properly followed, a good battery may be needlessly
replaced (Fig. 11).
(1) Measure the voltage at battery posts with a
voltmeter accurate to 1/10 volt (Fig. 12). If below 10
volts, charge current will be low, and it could take
some time before it accepts a current in excess of a
few milliamperes. Such low current may not be
detectable on amp meters built into many chargers.
(2) Connect charger leads. Some chargers feature
polarity protection circuitry that prevents operation
unless charger is connected to battery posts correctly.
A completely discharged battery may not haveenough voltage to activate this circuitry. This may
happen even though the leads are connected properly.
(3) Battery chargers vary in the amount of voltage
and current they provide. For the time required for
the battery to accept measurable charger current at
various voltages, refer to (Fig. 11). If charge current
is still not measurable after charging times, the bat-
tery should be replaced. If charge current is measur-
able during charging time, the battery may be good,
and charging should be completed in the normal
manner.VISUAL INSPECTION
CAUTION: Do not allow baking soda solution to
enter vent holes, as damage to battery can result.
(1) Clean top of battery with a solution of warm
water and baking soda.
(2) Apply soda solution with a bristle brush and
allow to soak until acid deposits loosen (Fig. 13).
(3) Rinse soda solution from battery with clear
water and blot battery dry with paper toweling. Dis-
pose of toweling in a safe manner. Refer to the
WARNINGS on top of battery.
(4) Inspect battery case and cover for cracks, leak-
age or damaged hold down ledge. If battery is dam-
aged replace it.
Fig. 11 Charging Rate
Fig. 12 Voltmeter Accurate to 1/10 Volt (Connected)
NS/GSBATTERY 8A - 7
SERVICE PROCEDURES (Continued)

(5) Inspect battery tray for damage caused by acid
from battery. If acid is present, clean area with bak-
ing soda solution.
(6) Clean battery posts with a battery post clean-
ing tool (Fig. 14).
(7) Clean battery cable clamps with a battery ter-
minal cleaning tool (Fig. 15). Replace cables that are
frayed or have broken clamps.REMOVAL AND INSTALLATION
BATTERY
WARNING: TO PROTECT THE HANDS FROM BAT-
TERY ACID, A SUITABLE PAIR OF HEAVY DUTY
RUBBER GLOVES, NOT THE HOUSEHOLD TYPE,
SHOULD BE WORN WHEN REMOVING OR SERVIC-
ING A BATTERY. SAFETY GLASSES ALSO SHOULD
BE WORN.
REMOVAL
(1) Verify that the ignition switch and all accesso-
ries are OFF.
(2) Disconnect battery cable terminals from the
battery posts, negative first (Fig. 16).
3
(3) Remove battery hold down (Fig. 17).
(4) Remove battery from vehicle (Fig. 18).
INSTALLATION
Inspect and clean battery and attaching compo-
nents before installation.
(1) Install battery in vehicle making sure that bat-
tery is properly positioned on battery tray.
(2) Install battery hold down.
(3) Connect battery cable terminals, positive cable
first. Make sure the top of battery terminals are
flush with top of posts.
WARNING: DO NOT OVER TIGHTEN BATTERY
CABLE CLAMPS, DAMAGE TO CLAMPS CAN
RESULT.
Fig. 13 Cleaning Battery
Fig. 14 Cleaning Battery Post
Fig. 15 Cleaning Battery Cable Terminal
8A - 8 BATTERYNS/GS
SERVICE PROCEDURES (Continued)

CHARGING SYSTEM
CONTENTS
page page
GENERAL INFORMATION
OVERVIEW............................. 1
DESCRIPTION AND OPERATION
BATTERY TEMPERATURE SENSOR.......... 2
CHARGING SYSTEM OPERATION........... 1
ELECTRONIC VOLTAGE REGULATOR......... 2
GENERATOR............................ 2
DIAGNOSIS AND TESTING
CHARGING SYSTEM RESISTANCE TESTS..... 4
CHARGING SYSTEM...................... 2CURRENT OUTPUT TEST.................. 4
ON-BOARD DIAGNOSTIC SYSTEM TEST...... 7
REMOVAL AND INSTALLATION
GENERATORÐ2.4L ENGINE................ 9
GENERATORÐ3.0L ENGINE................ 9
GENERATORÐ3.3/3.8 L ENGINE........... 10
SPECIFICATIONS
GENERATOR........................... 11
TORQUE.............................. 11
GENERAL INFORMATION
OVERVIEW
The battery, starting, and charging systems oper-
ate with one another, and must be tested as a com-
plete 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 the battery, Group 8B covers the
starting system, and Group 8C covers the charging
system. Refer to Group 8W - Wiring Diagrams for
complete circuit descriptions and diagrams. We have
separated these systems to make it easier to locate
the information you are seeking within this Service
Manual. However, when attempting to diagnose any
of these systems, it is important that you keep their
interdependency in mind.
The diagnostic procedures used in these groups
include the most basic conventional diagnostic meth-
ods to the more sophisticated On-Board Diagnostics
(OBD) built into the Powertrain Control Module
(PCM). Use of an induction ammeter, volt/ohmmeter,
battery charger, carbon pile rheostat (load tester),
and 12-volt test lamp may 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 the
On-Board Diagnostics Test in Group 8C - Charging
System for more information.
DESCRIPTION AND OPERATION
CHARGING SYSTEM OPERATION
The charging system consists of:
²Generator
²Electronic Voltage Regulator (EVR) circuitry
within the Powertrain Control Module (PCM)
²Ignition switch (refer to Group 8D, Ignition Sys-
tem for information)
²Battery (refer to Group 8A, Battery for informa-
tion)
²Temperature is measured by a sensor in the
PCM circuitry
²Wiring harness and connections (refer to Group
8W, Wiring for information)
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.
The amount of DC current produced by the gener-
ator is controlled by the EVR (field control) circuitry,
contained within the PCM. This circuitry is con-
nected in series with the second rotor field terminal
and ground.
All vehicles are equipped with On-Board Diagnos-
tics (OBD). All OBD-sensed systems, including the
EVR (field control) circuitry, 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 On-
Board Diagnostic System Test in this group for more
information.
NSCHARGING SYSTEM 8C - 1

GENERATOR
The generator is belt-driven by the engine. It is
serviced only as a complete assembly. If the genera-
tor fails for any reason, the entire assembly must be
replaced.
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 Y type stator winding connections deliver the
induced AC current to 3 positive and 3 negative
diodes for rectification. From the diodes, rectified DC
current is delivered to the vehicle electrical system
through the generator, battery, and ground terminals.
Noise emitting from the generator may be caused
by:
²Worn, loose or defective bearings
²Loose or defective drive pulley
²Incorrect, worn, damaged or misadjusted drive
belt
²Loose mounting bolts
²Misaligned drive pulley
²Defective stator or diode
BATTERY TEMPERATURE SENSOR
The temperature sensor, in the PCM, is used to
determine the battery temperature. This temperature
data, along with data from monitored line voltage, is
used by the PCM to vary the battery charging rate.
System voltage will be higher at colder temperatures
and is gradually reduced at warmer temperatures.
ELECTRONIC VOLTAGE REGULATOR
The Electronic Voltage Regulator (EVR) is not a
separate component. It is actually a voltage regulat-
ing circuit located within the Powertrain Control
Module (PCM). The EVR is not serviced separately. If
replacement is necessary, the PCM must be replaced.
Operation:The amount of DC current produced
by the generator is controlled by EVR circuitry con-
tained within the PCM. This circuitry is connected in
series with the generators second rotor field terminal
and its ground.
Voltage is regulated by cycling the ground path to
control the strength of the rotor magnetic field. The
EVR circuitry monitors system line voltage and bat-
tery temperature (refer to Battery Temperature Sen-
sor for more information). It then compensates and
regulates generator current output accordingly. Also
refer to Charging System Operation for additional
information.
DIAGNOSIS AND TESTING
CHARGING SYSTEM
When the ignition switch is turned to the ON posi-
tion, battery potential will register on the voltmeter.
During engine cranking a lower voltage will appear
on the meter. With the engine running, a voltage
reading higher than the first reading (ignition in ON)
should register.
The following are possible symptoms of a charging
system fault:
²The voltmeter does not operate properly
²An undercharged or overcharged battery condi-
tion occurs.
Remember that an undercharged battery is often
caused by:
²Accessories being left on with the engine not
running
²A faulty or improperly adjusted switch that
allows a lamp to stay on. See Ignition-Off Draw Test
in Group 8A, Battery for more information.
The following procedures may be used to correct a
problem diagnosed as a charging system fault.
INSPECTION
(1) Inspect condition of battery cable terminals,
battery posts, connections at engine block, starter
solenoid and relay. They should be clean and tight.
Repair as required.
(2) Inspect all fuses in the fuseblock module and
Power Distribution Center (PDC) for tightness in
receptacles. They should be properly installed and
tight. Repair or replace as required.
(3) Inspect the electrolyte level in the battery.
Replace battery if electrolyte level is low.
(4) Inspect generator mounting bolts for tightness.
Replace or tighten bolts if required. Refer to the Gen-
erator Removal/Installation section of this group for
torque specifications.
(5) Inspect generator drive belt condition and ten-
sion. Tighten or replace belt as required. Refer to
Belt Tension Specifications in Group 7, Cooling Sys-
tem.
(6) Inspect automatic belt tensioner (if equipped).
Refer to Group 7, Cooling System for information.
(7) Inspect connections at generator field, battery
output, and ground terminals. Also check ground con-
nection at engine. They should all be clean and tight.
Repair as required.
8C - 2 CHARGING SYSTEMNS
DESCRIPTION AND OPERATION (Continued)