Slow CHRYSLER VOYAGER 2004 User Guide

CONDITION POSSIBLE CAUSES CORRECTION4. Leaking piston seal. 4. Replace piston seal or brake caliper.
5. Suspension problem. 5. Refer to the Suspension group.
PARKING BRAKE -
EXCESSIVE HANDLE
TRAVEL 1. Rear drum brakes or rear disc
brake parking brake shoes out of
adjustment. 1. Adjust rear drum brake shoes, or
rear parking brake shoes on vehicles
with rear disc brakes.
STANDARD PROCEDURE - BASE BRAKE
BLEEDING
NOTE: This bleeding procedure is only for the vehi-
cle's base brakes hydraulic system. For bleeding
the antilock brakes hydraulic system, (Refer to 5 -
BRAKES - ABS - STANDARD PROCEDURE)
CAUTION: Before removing the master cylinder
cover, thoroughly clean the cover and master cylin-
der fluid reservoir to prevent dirt and other foreign
matter from dropping into the master cylinder fluid
reservoir.
NOTE: The following wheel sequence should be
used when bleeding the brake hydraulic system.
The use of this wheel sequence will ensure ade-
quate removal of all trapped air from the brake
hydraulic system.
² Left Rear Wheel
² Right Front Wheel
² Right Rear Wheel
² Left Front Wheel
NOTE: When bleeding the brake system, some air
may be trapped in the brake lines or valves far
upstream, as much as ten feet from the bleeder
screw (Fig. 1). Therefore, it is essential to have a
fast flow of a large volume of brake fluid when
bleeding the brakes to ensure all the air gets out. The brakes may be manually bled or pressure bled.
Refer to the appropriate following procedure.
MANUAL BLEEDING PROCEDURE
NOTE: Correct manual bleeding of the brakes
hydraulic system will require the aid of a helper.
NOTE: To adequately bleed the brakes using the
manual bleeding procedure the rear brakes must be
correctly adjusted. Prior to the manual bleeding of
the brake hydraulic system, correctly adjust the
rear brakes. (1) Pump the brake pedal three or four times and
hold it down before the bleeder screw is opened. (2) Push the brake pedal toward the floor and hold
it down. Then open the left rear bleeder screw at
least 1 full turn. When the bleeder screw opens the
brake pedal will drop all the way to the floor.
CAUTION: ªJust crackingº the bleeder screw often
restricts fluid flow, allowing only a slow, weak fluid
discharge of fluid. This practice will NOT get all the
air out. Make sure the bleeder is opened at least 1
full turn when bleeding.
(3) Release the brake pedal only afterthe bleeder
screw is closed. (4) Repeat steps 1 through 3, four or five times, at
each bleeder screw in the proper sequence. This
should pass a sufficient amount of fluid to expel all
the trapped air from the brake system. Be sure to
monitor the fluid level in the master cylinder, so it
stays at a proper level so air will not enter the brake
system through the master cylinder. (5) Check pedal travel. If pedal travel is excessive
or has not been improved, enough fluid has not
passed through the system to expel all the trapped
air. Continue to bleed system as necessary. (6) Perform a final adjustment of the rear brake
shoes (when applicable), then test drive vehicle to be
sure brakes are operating correctly and that pedal is
solid.
Fig. 1 Trapped Air In Brake Fluid Line
1 - TRAPPED AIR
RS BRAKES5s-7
BRAKES - BASE (Continued)

PRESSURE BLEEDING PROCEDURE
CAUTION: Use bleeder tank Special Tool C-3496-B
or equivalent with Adapter, Special Tool 6921, to
pressurize the hydraulic system for bleeding.Follow pressure bleeder manufacturer's instruc-
tions for use of pressure bleeding equipment. (1) Install the Adapter Master Cylinder Pressure
Bleed Cap, Special Tool 6921 on the fluid reservoir of
the master cylinder (Fig. 2). Attach the fluid hose
from the pressure bleeder to the fitting on Special
Tool 6921.
(2) Attach a clear plastic hose to the bleeder screw
at one wheel and feed the hose into a clear jar con-
taining fresh brake fluid. (3) Open the left rear wheel bleeder screw at least
one full turn or more to obtain an adequate flow of
brake fluid.
CAUTION: ªJust crackingº the bleeder screw often
restricts fluid flow, allowing only a slow, weak fluid
discharge of fluid. This practice will NOT get all the
air out. Make sure the bleeder is opened at least 1
full turn when bleeding.
(4) After 4 to 8 ounces of brake fluid has been bled
through the hydraulic system, and an air-free flow is
maintained in the hose and jar, this will indicate a
good bleed of the hydraulic system has been
obtained. (5) Repeat the procedure at all the other remain-
ing bleeder screws. (6) Check pedal travel. If pedal travel is excessive
or has not been improved, enough fluid has not
passed through the system to expel all the trapped
air. Be sure to monitor the fluid level in the pressure bleeder, so it stays at a proper level so air will not
enter the brake system through the master cylinder.
(7) Perform a final adjustment of the rear brake
shoes (when applicable), then test drive vehicle to be
sure brakes are operating correctly and that pedal is
solid.
SPECIFICATIONS
BRAKE FASTENER TORQUE
DESCRIPTION N´m Ft.
Lbs. In.
Lbs.
ABS ICU Mounting Bolts To
Bracket 11 Ð 9 7
ABS ICU Mounting
Bracket-To-Cradle Bolts 28 21 250
ABS CAB-To-HCU Mounting
Screws 2Ð17
ABS Wheel Speed Sensor
Head Mounting Bolt - Front 13 Ð 115
ABS Wheel Speed Sensor
Head Mounting Bolt - Rear 10 Ð 90
Adjustable Pedal Position
Sensor Mounting Screws 7.5 66 Ð
Adjustable Pedal Module
Mounting Screws 2.0 15 Ð
Brake Tube Nuts 17 Ð 145
Brake Hose Intermediate
Bracket Bolt 12 Ð 105
Brake Hose-To-Caliper
Mounting Bolt 47 35 Ð
Disc Brake Caliper Guide
Pin Bolts 35 26 Ð
Disc Brake Caliper Bleeder
Screw 15 Ð 125
Drum Brake Wheel Cylinder
Mounting Bolts 8Ð75
Drum Brake Wheel Cylinder
Mounting Bleeder screw 10 Ð 80
Drum Brake Support Plate
Mounting Bolts 130 95 Ð
Junction Block (Non-ABS
Brakes) Mounting Bolts 28 21 250
Master Cylinder Mounting
Nuts 25 19 225
Power Brake Booster
Mounting Nuts 28 21 250
Fig. 2 Tool 6921 Installed On Master Cylinder
1 - SPECIAL TOOL 6921
2 - FLUID RESERVOIR
5s - 8 BRAKESRS
BRAKES - BASE (Continued)

(4) Using a wooden dowel as a pushrod (Fig. 47),
slowly depress master cylinder pistons, then release
pressure, allowing pistons to return to released posi-
tion. Repeat several times until all air bubbles are
expelled. Make sure fluid level stays above tips of
bleeder tubes in reservoir while bleeding. (5) Remove bleeder tubes from master cylinder
outlet ports, then plug outlet ports and install fill cap
on reservoir. (6) Remove master cylinder from vise.
(7) Install master cylinder on vehicle. (Refer to 5 -
BRAKES - BASE/HYDRAULIC/MECHANICAL/MAS-
TER CYLINDER - INSTALLATION)
REMOVAL
REMOVAL - LHD
CAUTION: Vacuum in the power brake booster must
be pumped down (removed) before removing mas-
ter cylinder from power brake booster. This is nec-
essary to prevent the power brake booster from
sucking in any contamination as the master cylin-
der is removed. This can be done simply by pump-
ing the brake pedal, with the vehicle's engine not
running, until a firm feeling brake pedal is achieved.
(1) With engine not running, pump brake pedal
until a firm pedal is achieved (4-5 strokes). (2) Disconnect negative battery terminal. (3) Disconnect positive battery terminal.
(4) Remove battery shield.
(5) Remove nut and clamp securing battery to tray,
remove battery. (6) Thoroughly clean all surfaces of the brake fluid
reservoir and master cylinder. Use only solvent such
as Mopar tBrake Parts Cleaner or equivalent.
(7) Remove wiring harness connector from brake
fluid level switch in master cylinder brake fluid res-
ervoir (Fig. 48).
(8) Disconnect primary and secondary brake tubes
from master cylinder housing (Fig. 48). Install seal-
ing plugs in the now open brake tube outlet ports.
CAUTION: Before removing the master cylinder
from the power brake vacuum booster, the master
cylinder and vacuum booster must be thoroughly
cleaned. This must be done to prevent dirt particles
from falling into the power brake vacuum booster.
(9) Clean area where master cylinder assembly
attaches to power brake booster. Use only a solvent
such as Mopar tBrake Parts Cleaner or equivalent.
(10) Remove two nuts attaching master cylinder to
power brake booster (Fig. 49). (11) Slide master cylinder straight out of power
brake booster.
CAUTION: A seal on the rear of the master cylinder
is used to create the seal for holding vacuum in the
power brake vacuum booster. The vacuum seal on
the master cylinder MUST be replaced whenever the
master cylinder is removed from the power brake
vacuum booster.
Fig. 47 Master Cylinder Set Up For Bleeding
1 - BLEEDER TUBES 8358
2 - WOODEN DOWEL
3 - ADAPTER 8822-2 (USE ONLY ON TRACTION CONTROL
EQUIPPED MASTER CYLINDERS)
4 - ADAPTER 8822-2 (USE ONLY ON TRACTION CONTROL
EQUIPPED MASTER CYLINDERS)
Fig. 48 MASTER CYLINDER AND BOOSTER
1 - POWER BRAKE BOOSTER
2 - BOOSTER IDENTIFICATION LABEL
3 - FLUID LEVEL SWITCH CONNECTOR
4 - PRIMARY BRAKE TUBE NUT
5 - SECONDARY BRAKE TUBE NUT
6 - MASTER CYLINDER
RS BRAKES5s-35
MASTER CYLINDER (Continued)

INSTALLATION
GENERATOR AND AIR CONDITIONING BELT
(1) Install belt onto all pulleys except for the
crankshaft (Fig. 5).
(2) Rotate belt tensioner clockwise until belt can
be installed onto the crankshaft pulley (Fig. 2).
Slowly release belt tensioner.
(3) Verify belt is properly routed and engaged on
all pulleys (Fig. 5).
(4) Install drive belt shield (Fig. 7) and lower vehi-
cle.
POWER STEERING PUMP
(1) Install belt over crankshaft and power steering
pump pulleys (Fig. 5).
(2) Apply an initial snug torque to pivot bolt (3)
and front locking nut (2) (Fig. 3).
(3) Tighten adjusting bolt (4) until proper belt ten-
sion is obtained (Fig. 3). For belt tension check pro-
cedure, (Refer to 7 - COOLING/ACCESSORY DRIVE/
DRIVE BELTS - STANDARD PROCEDURE -
CHECKING POWER STEERING BELT TENSION).
(4) Tighten pivot bolt (3) and front locking nut (2)
to 54 N´m (40 ft. lbs.) (Fig. 3).
(5) Tighten rear locking nut (1) to 54 N´m (40 ft.
lbs.) (Fig. 3).
ADJUSTMENTS
Satisfactory performance of the belt driven accesso-
ries depends on proper belt tension. Belt tensioning
should be performed with the aid of Special Tool
7198. Because of space limitations in the engine com-
partment, the use of this gauge may be restricted.
Raise the vehicle on a hoist and the remove the
splash shield to gain access to the drive belts, if nec-
essary. Adjust belt tension for either aNeworUsed
belt. For specifications, (Refer to 7 - COOLING/AC-
CESSORY DRIVE - SPECIFICATIONS).
BELT TENSIONER - 2.4L
REMOVAL
(1) Raise vehicle on hoist.
(2) Remove the drive belt shield.
(3) Remove the generator/A/C drive belt. (Refer to
7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
(4) Remove the belt tensioner (Fig. 6).
INSTALLATION
(1) Install belt tensioner and bolt (Fig. 6). Tighten
bolt to 54 N´m (40 ft. lbs.).
(2) Install generator/A/C compressor drive belt.
(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE
BELTS - INSTALLATION)
(3) Install splash shield.
(4) Lower the vehicle.
Fig. 5 Accessory Drive Belts - 2.4L
1 - POWER STEERING PUMP PULLEY
2 - BELT TENSIONER
3 - GENERATOR PULLEY
4 - BELT - A/C AND GENERATOR
5 - A/C COMPRESSOR PULLEY
6 - CRANKSHAFT PULLEY
7 - BELT - POWER STEERING
Fig. 6 Belt Tensioner - 2.4L
1 - BELT TENSIONER
2 - GENERATOR BRACKET
3 - BOLT
7 - 10 ACCESSORY DRIVERS
DRIVE BELTS - 2.4L (Continued)

INSTALLATION
(1) Route and position the drive belt onto all pul-
leys, except for the crankshaft (Fig. 10).
(2) Rotate belt tensioner counterclockwise until
belt can be installed onto the crankshaft pulley (Fig.
8). Slowly release belt tensioner.
(3) Verify belt is properly routed and engaged on
all pulleys.
(4) Install drive belt shield (Fig. 7) and lower vehi-
cle.
BELT TENSIONER - 3.3/3.8L
REMOVAL
(1) Raise vehicle on hoist.
(2) Remove the drive belt shield.
(3) Remove the drive belt. (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS - REMOVAL)
(4) Remove the belt tensioner (Fig. 11).
INSTALLATION
(1) Install the belt tensioner and bolt (Fig. 11).
Tighten bolt to 28 N´m (250 in. lbs.).
(2) Install the drive belt. (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION)
(3) Install the drive belt shield.
(4) Lower the vehicle.
Fig. 10 ACCESSORY DRIVE BELT
1 - DRIVE BELT
2 - POWER STEERING PUMP PULLEY
3 - BELT TENIONER PULLEY
4 - IDLER PULLEY
5 - GENERATOR PULLEY
6 - AIR CONDITIONING COMPRESSOR PULLEY
7 - CRANKSHAFT PULLEY
8 - WATER PUMP PULLEY
Fig. 11 BELT TENSIONER - 3.3/3.8L
1 - BELT TENSIONER
2 - BOLT
7 - 12 ACCESSORY DRIVERS
DRIVE BELTS - 3.3/3.8L (Continued)

ENGINE
DIAGNOSIS AND TESTING - ENGINE COOLING
SYSTEM
Establish what driving condition caused the cooling
system complaint. The problem may be caused by an
abnormal load on the system such as the following:
prolonged idle, very high ambient temperature, slight
tail wind at idle, slow traffic speed, traffic jam, high
speed, steep grade.
DRIVING TECHNIQUES
To avoid overheating the cooling system:
(1) Idle with A/C off when temperature gauge is at
end of normal range.
(2) Do not increase engine speed for more air flow
and coolant flow because the electric motor fan sys-
tems are not responsive to engine RPM. The added
cooling from higher coolant flow rate is more than
offset by increased heat rejection (engine heat added
to coolant).
TRAILER TOWING
Consult the owner's manual under Trailer Towing
and do not exceed specified limits.
VISUAL INSPECTION
If the cooling system problem is not caused by a
driving condition, perform a visual inspection to
determine if there was a recent service or accident
repair, including the following:
²Loose/damaged water pump drive belt
²Incorrect cooling system refilling (trapped air or
low level)
²Brakes possibly dragging
²Damaged hoses
²Loose/damaged hose clamps
²Damaged/incorrect engine thermostat
²Damaged cooling fan motor, fan blade and fan
shroud
²Damaged head gasket
²Damaged water pump
²Damaged radiator
²Damaged coolant recovery system
²Damaged heater core
²Open/shorted electrical circuits
If the visual inspection reveals none of the above
as cause for a cooling system complaint, refer to the
following diagnostic charts.
COOLING SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
PRESSURE CAP IS BLOWING
OFF STEAM AND/OR COOLANT.
TEMPERATURE GAUGE READING
MAY BE ABOVE NORMAL BUT
NOT HIGH. COOLANT LEVEL MAY
BE HIGH IN COOLANT RESERVE/
OVERFLOW TANK.1. Pressure relief valve in radiator
cap is defective, or was not
properly seated.1. Check condition of radiator cap
and cap seal. (Refer to 7 -
COOLING/ENGINE/RADIATOR
PRESSURE CAP - DIAGNOSIS
AND TESTING) Replace cap as
necessary.
2. Incorrect cap was installed. 2. Replace cap as necessary.
3. Incorrect coolant mixture. 3. Check concentration level of the
coolant. (Refer to 7 - COOLING/
ENGINE/COOLANT - DIAGNOSIS
AND TESTING) Adjust the ethylene
glycol-to-water ratio as required.
COOLANT LOSS TO THE
GROUND WITHOUT PRESSURE
CAP BLOWOFF. GAUGE IS
READING HIGH OR HOT.1. Coolant leaks in radiator, cooling
system hoses, water pump or
engine.1. Pressure test and repair as
necessary. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING)
7 - 14 ENGINERS

OPERATION
The cooling system is equipped with a pressure cap
that releases excessive pressure; maintaining a range
of 97-124 kPa (14-18 psi).
The cooling system will operate at higher than
atmospheric pressure. The higher pressure raises the
coolant boiling point thus, allowing increased radia-
tor cooling capacity.
There is also a vent valve in the center of the cap.
This valve also opens when coolant is cooling and
contracting, allowing the coolant to return to cooling
system from coolant reserve system tank by vacuum
through a connecting hose.If valve is stuck shut,
or the coolant recovery hose is pinched, the
radiator hoses will be collapsed on cool down.
Clean the vent valve (Fig. 17) and inspect cool-
ant recovery hose routing, to ensure proper
sealing when boiling point is reached.
The gasket in the cap seals the filler neck, so that
vacuum can be maintained, allowing coolant to be
drawn back into the radiator from the reserve tank.
If the gasket is dirty or damaged, a vacuum
may not be achieved, resulting is loss of coolant
and eventual overheating due to low coolant
level in radiator and engine.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING SYSTEM
PRESSURE CAP TESTING
Dip the pressure cap in water. Clean any deposits
off the vent valve or its seat and apply cap to end of
the Pressure Cap Test Adaptor that is included with
the Cooling System Tester 7700 (Fig. 18). Working
the plunger, bring the pressure to 104 kPa (15 psi) on
the gauge. If the pressure cap fails to hold pressure
of at least 97 kPa (14 psi), replace the pressure cap.
CAUTION: The Cooling System Tester Tool is very
sensitive to small air leaks that will not cause cool-
ing system problems. A pressure cap that does not
have a history of coolant loss should not be
replaced just because it leaks slowly when tested
with this tool. Add water to the tool. Turn tool
upside down and recheck pressure cap to confirm
that cap is bad.
If the pressure cap tests properly while positioned
on Cooling System Tester (Fig. 18), but will not hold
pressure or vacuum when positioned on the filler
neck. Inspect the filler neck and cap top gasket for
irregularities that may prevent the cap from sealing
properly.
DIAGNOSIS AND TESTING - RADIATOR CAP
TO FILLER NECK SEAL
The pressure cap upper gasket (seal) pressure
relief can be checked by removing the overflow hose
at the radiator filler neck nipple (Fig. 19). Attach the
Radiator Pressure Tool to the filler neck nipple and
pump air into the radiator. Pressure cap upper gas-
ket should relieve at 69-124 kPa (10-18 psi) and hold
pressure at 55 kPa (8 psi) minimum.
Fig. 18 Testing Cooling System Pressure Cap
1 - PRESSURE CAP
2 - PRESSURE TESTER
Fig. 19 Radiator Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - RADIATOR
8 - FILLER NECK
RSENGINE7-27
RADIATOR PRESSURE CAP (Continued)

CHIME/BUZZER
TABLE OF CONTENTS
page page
CHIME/BUZZER
DESCRIPTION..........................1
OPERATION............................1WARNING.............................1
DIAGNOSIS AND TESTING - CHIME SYSTEM . . 1
CHIME/BUZZER
DESCRIPTION
The chime/buzzer system provides the driver with
warning chimes for:
²Seat Belt
²Exterior Lamps ON
²Key-In Ignition
²Engine Temperature Critical
²Turn Signals ON
²Dome Lamp ON
²Low Oil Pressure
²High Speed Warning
²Warning Lamp Announcement
²Key-In Accessory
²Low/High Tire Pressure
²Service Tire Pressure Monitor (TPM)
HIGH SPEED WARNING - EXPORT
The chime will sound, acting as a warning to the
driver that the vehicle speed has exceeded 120   3
kph (75   2 mph).
Refer to the proper Body Diagnostic Procedures
manual for further description of chimes.
OPERATION
Refer to the proper Body Diagnostic Procedures
manual for complete chime/buzzer operation and con-
ditions for operation.
HIGH SPEED WARNING - EXPORT
When the vehicle speed sensor sees 120 3kph
(75   2 mph), it sends a PCI data bus message to the
Body Control Module (BCM). The BCM then turns on
the chime to let the driver know that the vehicle has
reached a speed greater than 120 3kph(75 2
mph). This audible message will continue until the
vehicle is slowed below the predetermined speed.
WARNING
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
DIAGNOSIS AND TESTING - CHIME SYSTEM
Refer to the proper Body Diagnostic Procedures
manual for complete Diagnosis and Testing of the
Chime System.
NO TONE WHEN IGNITION SWITCH IS TURNED ON
AND DRIVER'S SEAT BELT IS NOT BUCKLED.
(1) Using a DRB llltscan tool, actuate chime
(BCM actuates).
(2) Using a voltmeter, check for voltage:
(a) BCM has two battery feeds at pin 1 and pin
5 of the 6±way connector.
(b) Pin 5 of the (BX2) 32 way connector of the
BCM for ignition feed.
(c) Check voltage (PX2) connector, pin 34 for 12v.
(d) If voltage OK, go to step Step 3
(e) If NO voltage repair as necessary. Refer to
the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, further details on
wire harness routing and retention, as well as pin-
out and location views for the various wire harness
connectors, splices and grounds.
RSCHIME/BUZZER8B-1

BATTERY SYSTEM DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
THE BATTERY STATE OF
CHARGE CANNOT BE
MAINTAINED.1. The battery has an
incorrect size or rating for
this vehicle.1. Refer to Battery System Specifications for the
proper specifications. Replace an incorrect
battery, as required.
2. The battery terminal
connections are loose or
corroded.2. Refer to Battery Cable for the proper cable
diagnosis and testing procedures. Clean and
tighten the battery terminal connections, as
required.
3. The electrical system
ignition-off draw is excessive.3. Refer to the IGNITION-OFF DRAW TEST
Standard Procedure for the proper test
procedures. Repair the faulty electrical system, as
required.
4. The battery is faulty. 4. Test the battery using the Micro 420 battery
tester. Refer to Standard Procedures for
additional test procedures. Replace the faulty
battery, as required.
5. The starting system is
faulty.5. Determine if the starting system is performing
to specifications. Refer to Starting System for the
proper starting system diagnosis and testing
procedures. Repair the faulty starting system, as
required.
6. The charging system is
faulty.6. Determine if the charging system is performing
to specifications. Refer to Charging System for
charging system diagnosis and testing
procedures. Repair the faulty charging system, as
required.
7. Electrical loads exceed the
output of the charging
system.7. Inspect the vehicle for aftermarket electrical
equipment which might cause excessive electrical
loads.
8. Slow driving or prolonged
idling with high-amperage
draw loads in use.8. Advise the vehicle operator, as required.
THE BATTERY WILL NOT
ACCEPT A CHARGE.1. The battery is faulty. 1. Test the battery using the Micro 420 battery
tester.. Charge or replace the faulty battery, as
required.
ABNORMAL BATTERY DISCHARGING
Any of the following conditions can result in abnor-
mal battery discharging:
1. A faulty or incorrect charging system compo-
nent. Refer to Charging System for additional charg-
ing system diagnosis and testing procedures.
2. A faulty or incorrect battery. Use Micro 420
tester and refer to Battery System for additional bat-
tery diagnosis and testing procedures.
3. A faulty circuit or component causing excessive
ignition-off draw.
4. Electrical loads that exceed the output of the
charging system. This can be due to equipmentinstalled after manufacture, or repeated short trip
use.
5. A faulty or incorrect starting system component.
Refer to Starting System for the proper starting sys-
tem diagnosis and testing procedures.
6. Corroded or loose battery posts and/or terminal
clamps.
7. Slow driving speeds (heavy traffic conditions) or
prolonged idling, with high-amperage draw loads in
use.
8F - 4 BATTERY SYSTEMRS
BATTERY SYSTEM (Continued)

found on the original equipment battery label. Be
certain that a replacement battery has the correct
Group Size number, as well as CCA, and RC or AH
ratings that equal or exceed the original equipment
specification for the vehicle being serviced. Refer to
Battery Specificationsin this group for the loca-
tion of the proper factory-installed battery specifica-
tions.
OPERATION
The battery is designed to store electrical energy in
a chemical form. When an electrical load is applied to
the terminals of the battery, an electrochemical reac-
tion occurs. This reaction causes the battery to dis-
charge electrical current from its terminals. As the
battery discharges, a gradual chemical change takes
place within each cell. The sulfuric acid in the elec-
trolyte combines with the plate materials, causing
both plates to slowly change to lead sulfate. At the
same time, oxygen from the positive plate material
combines with hydrogen from the sulfuric acid, caus-
ing the electrolyte to become mainly water. The
chemical changes within the battery are caused by
the movement of excess or free electrons between the
positive and negative plate groups. This movement of
electrons produces a flow of electrical current
through the load device attached to the battery ter-
minals.
As the plate materials become more similar chem-
ically, and the electrolyte becomes less acid, the volt-
age potential of each cell is reduced. However, by
charging the battery with a voltage higher than that
of the battery itself, the battery discharging process
is reversed. Charging the battery gradually changes
the sulfated lead plates back into sponge lead and
lead dioxide, and the water back into sulfuric acid.
This action restores the difference in the electron
charges deposited on the plates, and the voltage
potential of the battery cells. For a battery to remain
useful, it must be able to produce high-amperage cur-
rent over an extended period. A battery must also be
able to accept a charge, so that its voltage potential
may be restored.
The battery is vented to release excess hydrogen
gas that is created when the battery is being charged
or discharged. However, even with these vents,
hydrogen gas can collect in or around the battery. If
hydrogen gas is exposed to flame or sparks, it may
ignite. If the electrolyte level is low, the battery may
arc internally and explode. If the battery is equipped
with removable cell caps, add distilled water when-
ever the electrolyte level is below the top of the
plates. If the battery cell caps cannot be removed, the
battery must be replaced if the electrolyte level
becomes low.
DIAGNOSIS AND TESTING - BATTERY
The battery must be completely charged and the
terminals should be properly cleaned and inspected
before diagnostic procedures are performed. Refer to
Battery System Cleaning for the proper cleaning pro-
cedures, and Battery System Inspection for the
proper battery inspection procedures. Refer to Stan-
dard Procedures for the proper battery charging pro-
cedures.
MICRO 420 BATTERY TESTER
The Micro 420 automotive battery tester is
designed to help the dealership technicians diagnose
the cause of a defective battery. Follow the instruc-
tion manual supplied with the tester to properly
diagnose a vehicle. If the instruction manual is not
available refer to the standard procedure in this sec-
tion, which includes the directions for using the
Micro 420 battery tester.
WARNING: IF THE BATTERY SHOWS SIGNS OF
FREEZING, LEAKING OR LOOSE POSTS, DO NOT
TEST, ASSIST-BOOST, OR CHARGE. THE BATTERY
MAY ARC INTERNALLY AND EXPLODE. PERSONAL
INJURY AND/OR VEHICLE DAMAGE MAY RESULT.
WARNING: EXPLOSIVE HYDROGEN GAS FORMS IN
AND AROUND THE BATTERY. DO NOT SMOKE,
USE FLAME, OR CREATE SPARKS NEAR THE BAT-
TERY. PERSONAL INJURY AND/OR VEHICLE DAM-
AGE MAY RESULT.
WARNING: THE BATTERY CONTAINS SULFURIC
ACID, WHICH IS POISONOUS AND CAUSTIC. AVOID
CONTACT WITH THE SKIN, EYES, OR CLOTHING.
IN THE EVENT OF CONTACT, FLUSH WITH WATER
AND CALL A PHYSICIAN IMMEDIATELY. KEEP OUT
OF THE REACH OF CHILDREN.
A battery that will not accept a charge is faulty,
and must be replaced. Further testing is not
required. A fully-charged battery must be tested to
determine its cranking capacity. A battery that is ful-
ly-charged, but does not pass the Micro 420 or load
test, is faulty and must be replaced.
NOTE: Completely discharged batteries may take
several hours to accept a charge. Refer to Standard
Procedures for the proper battery charging proce-
dures.
RSBATTERY SYSTEM8F-9
BATTERY (Continued)