charging DODGE TRUCK 1993 Service Repair Manual

10 INTRODUCTION
•
INTERNATIONAL CONTROL AND DISPLAY SYMBOLS

ID

HIGH
BEAM P
FOG UGHTS -&
HEADLIGHTS,
PARKING UGHTS, PANEL UGHTS TURN SIGNAL A
HAZARD WARNING WINDSHIELD
WASHER
WINDSHIELD WIPER WINDSHIELD WIPER
AND WASHER WINDSCREEN DEMISTING
AND DEFROSTING *

VENTILATING
FAN 8
M f

REAR
WINDOW DEFOGGER
sp

REARWINLX)W WIPER
CD
l
m

REAR
WINDOW WASHER FUEL ENGINE COOLANT
TEMPERATURE BATTERY CHARGING
CONDITION ENGINE OIL

SEAT
BELT

(©) (®) ky

11 J

LIGHTER

BRAKE
FAILURE
PARKING
BRAKE
FRONT HOOD
REAR
HOOD

(TRUNK)
HORN
11 J

LIGHTER
93IN-9

INTERNATIONAL VEHICLE CONTROL AND DISPLAY

SYMBOLS
The graphic symbols illustrated in the chart below
are used to identify various instrument controls. The
symbols correspond to the controls and displays that are located on the instrument panel.

0-10
LUBRICATION
AND
MAINTENANCE

•

O.K.TO

JUMP
START BATTERY
CONDITION
INDICATOR DO NOT

JUMP
START J9100-26 DARKENED
INDICATOR
WITH
GREEN
DOT
•
LETTERS
Uk-
FLUID
Lt- E:L .

DARKENED
INDICATOR
NO
GREEN
DOT •
BATTERY CHARGE
10'//
• Ft UID
L
EVEl
OK
LIGHT
OR
BRIGHT
INDICATOR

•
RAT-cci,
C
H
A
P
C;
F
R^'^Owh

AM.w-GE
FlAf StIll BE
r-
•
!
F-
r tjr r
?
STA
F
•
r
O U n
C
AI:

Fig.
5
Battery
Condition indicator
(4) Attach a red jumper cable connector clamp to
the positive (4-) terminal on the booster battery. At­
tach the other red cable connector clamp to the pos­ itive (+) terminal on the discharged battery (Fig. 6).

CAUTION:
Do not
allow
the
positive (
+
)
and
nega­

tive
(-)
cable clamps
to
contact each other.
Do not
lean over
the
battery when connecting
the
cable

clamps.

WARNING:
DO NOT
CONNECT
A
JUMPER CABLE CONNECTOR CLAMP
TO THE
NEGATIVE POST
OF

THE DISCHARGED BATTERY.

(5) Connect a black jumper cable connector clamp
to the negative (-) terminal on the booster battery. Connect the other black jumper cable connector
clamp to a good ground source on the engine that is
to be started (Fig. 7).
Verify the engine ground (negative) contact
surface area is free of grease. Make sure there is
a good connection to bare metal. The engine
ground (negative) connection must provide good
electrical continuity.
(6) Start the engine.

WARNING:
THE
USE
OF ANY
JUMPER CABLE
DIS­
CONNECTION PROCEDURE OTHER THAN
THAT
DESCRIBED
BELOW COULD RESULT
IN:
• PERSONAL INJURY CAUSED BY BATTERY
ACID SQUIRTING FROM THE BATTERY VENTS
• PERSONAL INJURY AND/OR PROPERTY DAM­
AGE CAUSED BY BATTERY EXPLOSION
• DAMAGE TO THE BOOSTER VEHICLE OR THE
DISABLED VEHICLE CHARGING SYSTEM. (7) After the engine is started, the jumper cables
must be disconnected in the following order:
• Black (negative) cable connector clamp from the
engine ground contact • Black (negative) cable connector clamp from the
negative terminal (-) on the booster battery
• Red (positive) cable connector clamps from the pos­ itive
(
+ ) terminals on both batteries

BATTERY NEGATIVE
CABLE
TERMINAL POSITIVE
JUMPER
CABLE
BATTERY

J9000-37

Fig.
6 Positive
Jumper
Cable
Connection
ENGINE BATTERY
•GROUND NEGATIVE NEGATIVE
CABLE
-JUMPER
CABLE

BATTERY
J9000-38

Fig.
7
Both
Jumper
Cables
Connected
On
Disabled
Vehicle PORTABLE STARTING UNIT
There are many types of portable starting units
available for starting engines. Follow the manufac­
turer's instructions.

VEHICLE
LIFTING RECOMMENDATIONS
Refer to the Owner's Manual for emergency vehicle
lifting procedures.
FLOOR JACK When properly positioned, a floor jack can be used
to lift a vehicle (Fig. 8). Support the vehicle in the
raised position with jack stands at the front and rear ends of the frame rails.

CAUTION:
Do not
attempt
to lift a
vehicle with
a

floor jack positioned under:

0
- 21
LUBRICATION
AND
MAINTENANCE

• SERVICE INFORMATION
All vehicles are equipped with a maintenance-free
(MF) battery when shipped from the factory (Fig. 10).
A maintenance-free battery does not have removable
cell caps and does not require additional water. Each MF battery has a visual battery condition in­
dicator (Fig. 11). When an adequate battery charge

exists,
the indicator will have a GREEN dot. When
battery charging is necessary, the indicator will be dark. When the indicator is light brown colored or
yellow, the battery should be replaced.
INSPECTION

WARNING; WEAR SAFETY
GLASSES,
RUBBER
GLOVES
AND
PROTECTIVE CLOTHING WHEN SER­
VICING
A
BATTERY.
THE
BATTERY ELECTROLYTE CONTAINS SULFURIC ACID
AND
WILL CAUSE HARM
IF IT
CONTACTS SKIN, EYES
OR
CLOTHING.
IF SULFURIC ACID CONTACTS SKIN
OR
EYES,
GET

IMMEDIATE MEDICAL ATTENTION.
DO
NOT
SMOKE
IN
THE
VICINITY
OF A
BATTERY. KEEP OPEN
FLAMES
AND
SPARKS AWAY FROM BATTERY
FILLER CAPS BECAUSE EXPLOSIVE
GAS IS AL­

WAYS
PRESENT.

Battery maintenance should be completed before
the beginning of every winter season.
Use the following battery maintenance and inspec­
tion procedure. (1) Disconnect the battery negative cable and then
the positive cable.
(2) Clean the battery cables and terminal posts
with a wire brush and a battery terminal cleaner. (3) Remove the battery holddown strap. Clean the
battery tray with a solution of baking soda and wa­
ter. Rinse and dry the battery tray.
(4) Position the battery in the tray and install the
holddown strap. Do not over-tighten the nuts.
(5) Connect the battery positive cable and then the
negative cable to the battery.
(6) Apply a small amount of chassis lubricant (or
an equivalent protective coating) to the cable termi­

nals.

RUBBER/PLASTIC
COMPONENTS

INSPECTION Components should be inspected at the same time
as scheduled underhood maintenance is conducted.
Rubber/plastic components should be replaced imme­ diately if there is any evidence of wear. Inspect the exterior surface of rubber hoses and ny­
lon tubing for evidence of heat damage. The rubber
hose and nylon tubing located close to an exhaust
manifold should be given special attention. Verify
the nylon tubing located at these areas has not col­ lapsed.
INCREASED

ELECTROUTE CAPACITY
SEALED

VENT
CAPS TEST
INDICATOR ENVELOPE

SEPARATORS
BATTERY
HOLD DOWN
RK92

Fig. 10 Maintenance-Free (MF)
Battery

O.K. TO
JUMP START
BATTERY

CONDITION
INDICATOR
J9100-26
DARKENED
INDICATOR
WITH
GREEN
DOT
•
BATTERY CHARGE
OK '
•
FLUID LEVEL
OK

DARKENED
INDICATOR
NO
GREEN
DOT
•
BATTERY CHARGE
LOW
FLUID LEVEL
OK
LIGHT
OR
BRIGHT INDICATOR

•
BATTERY CHARGE UNKNOWN

•
FLUID uEv'EL
LOW
(CHARGE
MAY
STILL
BE
SUFFICIENT
TO
START YOUR
CAR)
Fig. 11
Battery
Condition Indicator
Inspect all the hose connections. Verify they are se­
cure and there is no fluid leakage.
ENGINE MOUNTS Inspect the rubber in the engine mounts for exces­
sive wear. Slight wear at the ends will not affect the
functioning of an engine mount. If excessive engine
movement is detected, the engine mount(s) should be
replaced.

DRIVE
BELTS

MAINTENANCE SCHEDULE Replace the drive belt(s) and adjust the drive ten­
sion at the interval specified in maintenance sched­

ule.
If necessary, refer to Group 7—Cooling Systems.

•

COOLING SYSTEM
7 - 15
SERVICE
PROCEDURES

INDEX
page
Coolant
26
Coolant Reserve/Overflow System
30

Cooling System Cleaning/Reverse Flushing
28

Cooling System Fan—Diesel Engine
. 37

Cooling System
Fan—Gas
Engines
36

Cooling System
Hoses
34
Draining Cooling System
27

Pressure
Testing
Radiator
Caps
............. 32

Radiator Pressure
Cap 31

Radiators
32

Refilling
the
Cooling System
28

WATER PUMPS—EXCEPT DIESEL
A centrifugal water pump circulates coolant
through the water jackets, passages, intake manifold,
radiator core, cooling system hoses and heater core.
The pump is driven from the engine crankshaft by a drive belt. The water pump impeller is pressed onto the rear
of a shaft that rotates in a bearing pressed into the
water pump body. The body has a small hole for ven­
tilation. The water pump seals are lubricated by an­
tifreeze in the coolant mixture. Additional lubrication is not necessary. A quick test to determine if pump is working is to
check if heater warms properly. A defective water
pump will not be able to circulate heated coolant
through the long heater hose to the heater core. The water pump on all models can be removed
without discharging the air conditioning system (if equipped).
REMOVAL The water pump on all gas powered engines is
bolted directly to the engine timing chain case/cover.
A gasket is used as a seal between the water pump
and timing chain case/cover.
If water pump is replaced because of bearing/shaft
damage or leaking shaft seal, the mechanical cooling
fan assembly should also be inspected. Inspect for fa­ tigue cracks, loose blades or loose rivets that could
have resulted from excessive vibration. Replace fan if any of these conditions are found. Also check condi­
tion of the thermal viscous fan drive. Refer to Vis­
cous Fan Drive in this group. (1) Disconnect negative battery cable from battery.
(2) Drain cooling system. Refer to Draining Cool­
ing System in this group. Do not waste reusable coolant. If solution is clean,
drain coolant into a clean container for reuse.
(3)
Disconnect throttle cable from clip at top of fan
shroud.
page

Testing
Cooling System
for
Leaks
. 29

Thermostat
22

Transmission
Oil
Cooler—Diesel
35

Transmission
Oil
Cooler—Except Diesel
35

Transmission Oil-To-Air Cooler
36
Viscous
Fan
Drive
38

Water
Pump
Bypass
Hose—All
Gas
Powered
Engines
.............................. 19

Water
Pumps—5.9L Diesel
18

Water
Pumps—Except Diesel
15
(4) Unsnap coolant reserve/overflow tank (up and
out) from the T-slots on side of fan shroud (Fig. 1) and lay aside. Do not disconnect hose or drain cool­
ant from tank.
(5) Remove the fan shroud from the radiator. Do
not remove shroud from vehicle at this time.
FAN

SHROUD
J9107-67

Fig.
1 Fan
Shroud—Except
Diesel

(6) Remove upper radiator hose at radiator. Special
Clamp Tool number 6094 (Fig. 2) may be used to re­
move the constant tension clamps.
(7) The thermal viscous fan drive is attached
(threaded) to the water pump hub shaft (Fig. 3). Re­
move the fan/fan drive assembly from water pump by
turning the mounting nut counterclockwise (as viewed from front). Threads on the fan drive are RIGHT HAND. A Snap-On 36 MM Fan Wrench (number SP346 from Snap-On Cummins Diesel Tool
Set number 2017DSP) can be used. Place a bar or
screwdriver between the water pump pulley bolts (Fig. 3) to prevent the pulley from rotating.
If water pump is being replaced, do not unbolt fan
blade assembly (Fig. 3) from the thermal control fan drive.

7 - 20
COOLING
SYSTEM

•

HOSE
CLAMP
HOSE

J9207-36
Fig.
16
Hose
Clamp
Tool
WITH AIR
CONDITIONING
(A/C)

REMOVAL
If equipped with A/C, the generator and A/C com­
pressor along with their common mounting bracket (Fig. 17) must be partially removed. Removing the
generator or A/C compressor from their mounting
bracket is not necessary. Also, discharging the A/C system is not necessary. Do not remove any refrig­
erant lines from A/C compressor.

SUPPORT BRACKET (ROD)
GENERATOR/COMPRESSOR
MOUNTING
BRACKET

J9307-66

Fig.
17 Generator—A/C
Compressor
Mounting
Bracket—
Typical

WARNING;
THE A/C
SYSTEM
IS
UNDER
PRESSURE
EVEN
WITH
THE
ENGINE OFF. REFER
TO
REFRIG­

ERANT
WARNINGS
IN
GROUP
24,
HEATING
AND

AIR
CONDITIONING.

(1) Disconnect negative battery cable from battery. (2) Partially drain cooling system. Refer to Drain­
ing Cooling System in this group.
Do not waste reusable coolant. If the solution is
clean, drain the coolant into a clean container for re­
use.

(3) Remove upper radiator hose clamp at radiator.
Special Clamp Tool number 6094 (Fig. 16) may be
used to remove the constant tension clamps. Remove
hose at radiator.
(4) Disconnect throttle cable from clip at radiator
fan shroud. (5) Unplug wiring harness from A/C compressor.
(6) Remove the air cleaner assembly.
(7) Remove accessory drive belt. Refer to Belt Re­
moval/Installation in the Engine Accessory Drive
Belt section of this group.
(8) 3.9L/5.2L/5.9L LDC-Gas: The drive belt idler
pulley must be removed to gain access to one of the
A/C compressor/generator bracket mounting bolts. Remove the idler pulley bolt and remove idler pulley (Fig. 18).

GENERATOR/COMPRESSOR
AND
BRACKET

SUPPORT BRACKET

IGNITION

COIL
BRACKET
Fig.
18 Idler Pulley-3.9U5.2U5.9L
LDC-Gas
Engine
5.9L HDC-Gas: The automatic belt tensioner/pul-
ley assembly must be removed to gain access to one
of the A/C compressor/generator bracket mounting

bolts.
Remove the tensioner mounting bolt (Fig. 19) and remove tensioner.
(9) Remove the engine oil dipstick tube mounting
bolt at the side of the A/C-generator mounting
bracket.
(10) Disconnect throttle body control cables. Refer
to Accelerator Pedal and Throttle Cable in Group 14,
Fuel System.

•

ELECTRICAL
ELECTRICAL
8A - 1

Group

AUDIO
SYSTEMS
8F
BATTERY/STARTER/GENERATOR
SERVICE
.. 8B
BATTERY/STARTING/CHARGING
SYSTEMS

DIAGNOSTICS
8A

HORNS
8G

IGNITION
SYSTEMS
8D
INSTRUMENT PANEL AND
GAUGES
8E

LAMPS
8L

POWER
LOCKS
8P
INDEX

Group

POWER
MIRRORS
8T

POWER
WINDOWS 8S

REAR
WINDOW DEFOGGER 8N
TURN
SIGNALS
AND HAZARD WARNING
FLASHERS
8J
VEHICLE
SPEED
CONTROL SYSTEM 8H WARNING BUZZER SYSTEM 8U
WINDSHIELD WIPERS AND
WASHERS
8K
WIRING DIAGRAMS 8W

BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS
CONTENTS
page
page
BATTERY TEST
PROCEDURES
2 GENERATOR TEST
PROCEDURES
ON VEHICLE . 13

ENGINE
STARTER MOTOR TEST
PROCEDURES
..9 SPECIFICATIONS 18

GENERAL
INFORMATION 1

GENERAL INFORMATION

The Battery, Starting, and Charging Systems oper­
ate with one another, and therefore, must be thor­
oughly tested as a complete system. In order for the
vehicle to start and charge properly, it must have a
battery that will perform to specifications. The starter
motor, generator, wiring, and electronics also must
perform within specifications. Group 8A covers Start­ ing (Fig. 1) and Charging (Fig. 2) System diagnostic
procedures. These procedures include the most basic
conventional methods to On-Board Diagnostics (OBD)
built into the Powertrain Control Module (PCM).
Use of an ammeter, volt/ohmmeter, battery
charger, carbon pile rheostat (load tester), and 12
volt test light will be required.
All OBD sensing systems are monitored by the
PCM. The PCM will store in memory any detectable
failure in the monitored circuits. Refer to Using On-
Board Diagnostic System in this group for more in­ formation.
NEGATIVE

BATTERY
CABLE

A
7

POSITIVE

BATTERY
CABLE
BATTERY

J918A-11

Fig.
1 Starting
System
Components—Typical

8A
- 2
ELECTRICAL

•

MALFUNCTION
INDICATOR
LAMP

DIAGNOSTIC SCAN
TOOL

POWERTRAIN CONTROL
MODULE
GENERATOR
BATTERY

J938A-23

Fig.
2
Charging
System
Components—Typical
BATTERY TEST
PROCEDURES

INDEX

page

Battery
Charging
6

Battery
Load Test
5

Battery
Open
Circuit
Voltage Test
.............
4

Causes
of
Battery
Discharging
3

GENERAL
INFORMATION
The battery stores, stabilizes,
and
produces electri­
cal current.
A
battery must
be
able
to
accept
a

charge
and
produce high-amperage current over
an

extended period.
A
chemical reaction takes place
be­

tween sulfuric acid solution (electrolyte)
and
lead + /-
plates
in
each cell
of the
battery.
As the
battery discharges,
the
plates collect acid from
the
electro­

lyte.
When
the
charging system charges
the
battery,
water
is
converted
to
sulfuric acid
in the
battery.
The
amount
of
acid (specific gravity)
in the
electrolyte
can
be
measured with
a
hydrometer.
A
factory
in­
stalled battery
has a
built-in test indicator
to
help
determine state-of-charge.
The
factory installed bat­
tery
is
also nonrefillable, water
can not be
added.
The battery
is
vented
to
release gases that
are cre-
page

General
Information
2
Ignition
Off
Draw (IOD)
4

State
of
Charge Test Using Test
Indicator
.......
3

Test
Indicator
3

ated when
the
battery
is
being charged.
The
battery

top,
posts,
and
terminals should
be
cleaned when other underhood maintenance
is
performed (Fig.
3).

WARNING:
DO
NOT
ATTEMPT
TO
ASSIST BOOST, CHARGE,
OR
TEST BATTERY WHEN ELECTRO­LYTE LEVEL IS BELOW THE TOP
OF
THE PLATES
(YELLOW
OR
BRIGHT COLOR
IS
VISIBLE). PER­
SONAL
INJURY
MAY
OCCUR.

When
the
electrolyte level
is
below
the top of the

plates (yellow
or
bright indicator),
the
battery must
be replaced.
The
battery must
be
completely charged (green indicator)
and the top,
posts,
and
terminals
should
be
properly cleaned before diagnostic proce­
dures
are
performed. Refer
to
Group
8B -
Battery/ Starter Service,
for
additional information.

•

ELECTRICAL
8A - 3

Fig.
3
Battery
Construction
and
Test Indicator

TEST INDICATOR
A test indicator (hydrometer) built into
the top of

the battery case, provides visual information
for
bat­
tery testing (Fig.
4). The
test indicator
is to be
used with diagnostic procedures described
in
this group.
It
is important when using
the
test indicator that
the

battery
is
relatively level
and has a
clean
top to see
correct indications.
A
light
may be
required
to
view
indicator.

WARNING:
DO
NOT USE
OPEN FLAME. EXPLOSIVE
GASES
FORM ABOVE BATTERY.
Fig.
4
Built in Test Indicator

STATE
OF
CHARGE TEST USING TEST INDICATOR
The built-in test indicator (hydrometer) measures
the specific gravity
of
the electrolyte. Specific gravity (SG)
of the
electrolyte will indicate state-of-charge
(voltage); although,
the
test indicator will
not
indi­
cate cranking capacity
of the
battery. Refer
to
Bat­
tery Load Test
for
more information. Look into
the
sight glass
and
note
the
color
of the
indicator
(Fig.

5),
refer
to the
following description
as
color indi­

cates:
GREEN-75
to
100% state-of-charge
The battery
is
adequately charged
for
more testing
or return
to use. If the
vehicle will
not
crank
for a

maximum
15
seconds, refer
to
Battery Load Test
for

more information. BLACK
OR
DARK—0
to
75% state-of-charge The battery
is
inadequately charged
and
must
be

charged until green
dot is
visible
(12.4
volts
or

greater) before
the
battery
is
tested
or
returned
to

use.
Refer
to
Causes
of
Battery Discharging
for
more information.
YELLOW
OR
BRIGHT COLOR

WARNING:
DO NOT
ATTEMPT
TO
CHARGE, TEST,
OR
ASSIST
BOOST BATTERY WHEN YELLOW
OR

BRIGHT COLOR
IS
VISIBLE. PERSONAL INJURY
MAY OCCUR.

A yellow
or
bright color indicates water (electro­
lyte) level
in
battery
is
below
the
test indicator
(Fig.
5).
Water
can not be
added
to a
maintenance free
battery.
The
battery must
be
replaced.
A low
electro­ lyte level
may be
caused
by an
over charging condi­
tion. Refer
to
Generator Test Procedures
On
Vehicle in this group.

TEST INDICATOR/STATE
OF
CHARGE

IfVW,
"TCfV

REPLACE BATTERY

lUUTu
/Otu L
f
REPLACE BATTERY

SBl
ill,
iMMiMMMMSMM^MM

GREEN BLACK

YELLOW
898A-3
Fig.
5
Test Indicator
Sight Glass

CAUSES
OF
BATTERY DISCHARGING
It
is
normal
to
have
a
small
(5 to 20
milliamperes)
draw from
the
battery with
the
ignition
in the OFF

position,
and ALL
lamps OFF.
The
constant draw
is
due
to
various electronic features
or
accessories that
require electrical current with
the
ignition
OFF to

function properly.
If a
vehicle
is not
used
for a
period of
20
days
or
more,
the
black battery disconnect
should
be
disconnected.
The
disconnect
is
located
be­

hind
the
battery
on the
engine wiring harness. This will prevent battery discharging.

ABNORMAL
BATTERY
DISCHARGING
(1) Corroded battery posts
and
terminals.
(2) Loose
or
worn generator drive belt.
(3) Electrical loads that exceed
the
output
of the

charging system
due to
equipment
or
accessories
in­
stalled after delivery. (4) Slow driving speeds (heavy traffic conditions)
or prolonged idling with high-amperage electrical systems
in use.

(5) Defective electrical circuit
or
component caus­
ing excess Ignition
Off
Draw (IOD).
(6) Defective charging system.
(7) Defective battery.

8A
- 4
ELECTRICAL

•
IGNITION
OFF
DRAW
(IOD)
Ignition off draw refers to power being drained
from the battery with the ignition turned off. A nor­
mal vehicle electrical system will draw from 5 to 20
milliamps. A vehicle that has not been operated for
an extended period of time (approximately 20 days)
may discharge the battery to an inadequate level.
Battery drain should not exceed approximately 20
MA (20 milliamps = 0.020 amps). The 20 MA are needed to supply PCM memory,
digital clock memory, and ETR (electronically tuned
radio) memory. Excessive battery drain is caused by items left
turned on, internally shorted generator, or intermit­
tent short in wiring.
If the IOD is excessive (over 20 milliamperes), the
defect must be found and corrected before replacing a
battery. In most cases the battery can be charged and returned to service.
TEST PROCEDURE Testing for higher amperage IOD must be per­
formed first to prevent damage to most milliamp
meters.
Verify that all electrical accessories are OFF. Turn
off all lights, remove ignition key, and close all

doors.
If the vehicle is equipped with electronic acces­
sories (illuminated entry, high line radio), allow the
systems to automatically shut off (time out), up to 3
minutes.
(1) After determining that the underhood lamp is
operating properly then disconnect bulb. (2) Disconnect negative cable from battery.
(3) Connect a typical 12 volt test light (low watt­
age bulb) between the negative cable clamp and the
battery negative terminal. The test light may light brightly for up to 3 min­
utes or may not light at all (depending on the elec­
trical equipment). The term brightly being used
throughout the following tests, implies the bright­ ness of the test light will be the same as if it were
connected across the battery.
The test light must be securely clamped to the neg­
ative cable and battery terminal. If the test light be­
comes disconnected during any of the IOD test, the electronic timer function will be activated and all
tests must be repeated.
(4) After 3 minutes, the test light should turn OFF
or be DIMLY lit (depending on the electrical equip­

ment).
If the test light remains brightly lit do not
disconnect it. Remove each fuse or circuit breaker (refer to Group 8 - Wiring Diagrams) until test light
is either OFF or DIMLY lit. This will eliminate the
higher amperage draw.
If test light is still bright after disconnecting each
fuse and circuit breaker, disconnect the wiring har­ ness from the generator. Refer to Generator Testing
in this group. Do not disconnect the test light. After higher amperage IOD has been corrected, low
amperage IOD may be checked.
It is now safe to install milliamp meter to check for
low amperage IOD.
(5) With test light still connected, securely clamp
an ammeter between battery negative terminal and
negative battery cable.
If the test light or the milliamp meter circuit is
broken the various timer circuits will start. Do
not open any doors or turn on any electrical ac­ cessories with the test light disconnected or the
meter may be damaged.
(6) Disconnect test light. The current draw should
not exceed 0.020 amp. If it exceeds 20 milliamps iso­
late each circuit by removing circuit breakers and

fuses.
The meter reading drops once the high current
problem is found. Repair this section of the circuit,
whether it is a wiring short or component failure.

BATTERY
OPEN CIRCUIT VOLTAGE TEST
A battery voltage (no load) test will indicate the
state of charge of a battery that will pass the Battery
Load Test described in this section. Before proceed­
ing with this test or the Battery Load Test the
battery must be completely charged as de­ scribed in Battery Charging in this section. If a battery has a no load voltage reading of 12.4
volts or greater but will not endure a load test, it is
defective and should be replaced. Refer to Group 8B,
Battery/Starter Service for instructions. To test bat­
tery no load voltage, perform the following operation: (1) Before measuring open circuit voltage, the sur­
face charge must be removed from plates. Turn head lights on for 15 seconds then allow up to 5 minutes
for voltage to stabilize. (2) Remove both battery cables, negative first.
(3) Using a voltmeter connected to the battery

posts,
see instructions provided with voltmeter, mea­ sure open circuit voltage (Fig. 6). This voltage reading will indicate state of charge,
but will not reveal cranking capacity. Refer to Bat­
tery Open Circuit Voltage chart.
BATTERY OPEN CIRCUIT VOLTAGE
Open
Circuit
Volts

Percent
Chang©

11.7
volts
or
less
0%
12.0 25%
12.2 50%
12.4 75%

12.6
or more 100%
918A-3

•

ELECTRICAL
8A - i
898A-7

Fig.
6
Testing
Open
Circuit Voltage

BATTERY LOAD
TEST
WARNING:
IF
BATTERY SHOWS SIGNS
OF
FREEZ­
ING, LEAKING, LOOSE POSTS,
OR
EXCESSIVELY
LOW ELECTROLYTE LEVEL,
DO
NOT
TEST. ACID BURNS
OR
EXPLOSIVE
CONDITION
MAY
RESULT.

A battery load test will verify
the
actual cranking
performance based
on the
cold crank rating
of the

battery.
Before performing
the
battery load test,
the

battery must
be
FULLY CHARGED.
(1) Remove both battery cables, negative first. Bat­
tery
top and
posts should
be
clean.
If
green color
is
not visible
in
indicator, charge
the
battery,
see
Bat­
tery Charging Procedures
in
this section.
(2) Connect
a
suitable Volt-Ammeter-Load tester
(Fig.
7) to the
battery posts
(Fig. 8).
Refer
to
operat­
ing instructions provided with the.tester being used.
Check
the
open circuit voltage
(no
load)
of the
bat­
tery. Voltage should
be
equal
to or
greater than
12.4

volts
(Fig. 7)
with green color visible
in
test indica­
tor. 898A-8
INDUCTION

AMPMETER CLAMP
POSITIVE CLAMP NEGATIVE
CLAMP

J908A-12

Fig.
8
Volt-Ammeter-Load Tester
Connections
(3) Rotate
the
load control knob (Carbon pile rheo­
stat)
to
apply
a 300 amp
load
for 15
seconds then
control knob
to off
(Fig.
9).
This will remove
the
sur­
face charge from
the
battery.

Fig.
7
Volt-Amps-Load
Tester—
Typical
898A-10

Fig.
9
Remove
Surface
Charge
from
Battery

(4) Allow
the
battery
to
stabilize
to
open circuit
voltage
(may
take
up to 5
minutes).
(5) Rotate
the
load control knob
to
maintain
a
load

(50%
of
cold crank rating—see specifications)
for a

minimum
15
seconds
(Fig. 10).
After
15
seconds,
record
the
(loaded) voltage reading
and
return
the
load control
to off.

(6) Voltage drop will vary according
to
battery
temperature
at the
time
of the
load test. Battery
temperature
can be
estimated
by the
temperature
of
exposure over
the
preceding several hours.
If the
bat­
tery
has
been charged, boosted,
or
loaded
a few
min­ utes prior
to
test,
the
battery would
be
somewhat
warmer. Refer
to
Load Test Temperature chart
for

proper loaded voltage reading.
(7)
If
battery passes load test,
it is in
good condi­
tion.
No
further tests
are
necessary.
If it
fails load
test,
it
should
be
replaced.