1953 JEEP DJ alternator

'Jeep'
UNIVERSAL SERIES SERVICE
MANUAL

H
ELECTRICAL
SYSTEM

Contents

SUBJECT
PAR.

GENERAL
. -H-l Alternator Charging System H-6, 63 Battery. . . .H-2

Electrical
Instruments. H-l 11 Ignition System H-3

Lighting
System H-8, 125

Primary
Circuit.
.. H-4 Secondary
Circuit
H-5
SparkPlugs H-33
Starting System H-7, 88

DISTRIBUTOR
—
HURRICANE
F4
ENGINE
H-9
Coil
H-19 Condenser
.H-l
2
Disassembly.
.........................
.H-16
Distributor Cap H-10 Distributor
Points
H-13
Governor Mechanism H-l4
Inspection H-l
7
Installation and Timing H-18
Removal H-15
Rotor H-ll

DISTRIBUTOR
—
DAUNTLESS
V-6
ENGINE
H-20

Ballast
Resistor. H-32

Centrifugal
Advance H-25
Cleaning and Inspection H-28
Coil
H-31
Condenser H-23
Disassembly. H-27
Distributor Cap H-21 Distributor
Points
H-24
Installation and Timing. . .H-30
Reassembly. H-29
Removal H-2 6
Rotor H-2
2

GENERATOR CHARGING SYSTEM SERVICE
H-34 Generator Armature H-3
7

Generator Assembly. H-40
Generator
Brush
Holders H-39
Generator Disassembly H-36
Generator
Field
Coils.
H-38
Generator Maintenance H-35 Generator -
Current
-
Voltage
Regulator. . .H-41
Generator Regulator Quick Checks...... .H-48
Generator Regulator Test Procedure H-47

ALTERNATOR PRECAUTIONS.
H-64

ALTERNATOR CHARGING SYSTEM.
. .H-63 Alternator On-Vehicle Tests. .H-67
Alternator Output Test. .H-70 Isolation
Diode
Test H-69
Regulator Test .H-71 Removal and Installation of
Voltage
Regulator. H-72
SUBJECT
PAR.
Service
Diagnosis
H-66 Test Equipment H-68
Alternator
Field
Circuit
Test H-73
Brush
Insulation and Continuity Test H-75
Brush
Removal and Inspection H-74
Rotor In-Vehicle Tests H-76

ALTERNATOR BENCH TESTS.
.H-77

ALTERNATOR REMOVAL
H-78 Alternator Disassembly H-80 Alternator Installation. H-87
Assembling Alternator H-86
General
Inspection H-81
Diode
Test H-85

Out-Of-Circuit
Rotor Test. .H-82

Out-Of-Circuit
Stator Leakage Test.. . H-83 Rotor Tests H-79
Stator
Coil
Leakage and Continuity Test. .H-84

STARTING
MOTOR
—
PRESTOLITE.
. .H-92
Armature
.H-l
00 Bench Test H-l04
Bendix
Folo-Thru
Drive H-105

Brush
Holder Inspection. .H-102
Brushes H-98
Commutator H-95, 99
Disassembly H-9 7

Field
Coils H-101
Lubrication
of
Folo-Thru
Drive H-l06
Maintenance Procedure H-93
Overhaul
Procedure H-96
Reassembly of Starting Motor. .
H-l
03
Starter
Solenoid
Switch H-10 7 Starter Ignition Switch. .H-89

Wiring.
. . . H-94

STARTING
MOTOR
—DELCO
H-108
Armature
H-101
Brush
Holder Inspection H-l 15 Brushes
H:lll

Commutator H-112

Field
Coils........
H-114
Locked
Armature Test. . . H-l20

Solenoid
Coils H-l 16
Starting Motor Reassembly H-l 17
Starting Motor Cleaning and Inspection.
.H-l
10
Starting Motor Disassembly .H-109 Starting Motor No-Load Test H-119
Starting Motor Test — General H-l 18 Starter Switch —
Solenoid
Type. H-l21
Starter Ignition Switch. .H-89

ELECTRICAL
INSTRUMENTS
H-122 Testing Instrument Gauges H-l24

LIGHTING
SYSTEM
H-l25 Aiming Head Lamps H-132

Backup
Lamps H-135

(continued
on
next
page)
171

H

ELECTRICAL
SYSTEM SUBJECT
PAR.

Directional
Signal
Lamps
H-138

Hazard
Warning
Lamps
H-139

Head
Lamp
Replacement H-130
Head
Lamp
Aiming Procedure H-131 Headlight Dimmer Switch H-127

License
Plate
Lamp
H-136
Main
Light
Switch. H-126

Marker
Lights .H-l40

Parking
and
Turn
Signal
Light
H-133
Stop
Light
Switch. H-l28
Tail,
Stop and
Turn
Signal
Lamp
.H-134

H-1. GENERAL
All
'Jeep' Universal vehicles are equipped with 12- volt electrical systems. Use caution around the higher
voltage
of the 12-volt system as accidental

short
circuits are more capable of damaging electri­
cal
units. Also, arcs around the 12-volt battery are
more apt to ignite any gas that may be escaping

from
it. In the following paragraphs
will
be found
information about the battery, distributor, coil,
generator, alternator,
voltage
regulator and start­ ing motor. These units with the connecting wires,

make
up the
engine
electrical system. The wiring
diagram
will
show the different circuits of the en­

gine
electrical system and the various units which
make
up
those
circuits.

With
plastic-covered wiring harnesses use only

rubber-insulated
wiring clips.

Caution:
All current production vehicles are 12- volt, negative ground. Whenever servicing a 12-
volt electrical system, use caution, as an accidental

short
circuit is capable of damaging electrical units. Disconnect battery ground cable before changing

electrical
components.

H-2.
Battery

The
battery is a storage reservoir for electrical
energy produced by the alternator or generator.
The
battery should store sufficient energy for
operation of the entire electrical system when the
alternator
or generator is not pr 1,scing output,

such
as when the ignition is first turned on. Of

particular
importance is maintaining the electrolyte
at the correct level, regularly checking with a
hydrometer, and maintaining clean, tight cable connections.

Battery
service information is given in this section.

Caution:
Do not allow flames or sparks to be
brought near the vent
openings
of the battery since
hydrogen gas may be present in the battery and might explode.

Note:
The liquid in the battery (electrolyte) is a
solution of sulphuric acid which, on contact, can

injure
skin or
eyes,
or damage clothes. If it is spilled
on the skin or spattered in the
eyes,
promptly flush
it
away with quantities of clear water only. If the

acid
is spilled on clothes, wet it thoroughly with a

weak
solution of ammonia, or with a solution of sodium bicarbonate or baking soda.
SUBJECT
PAR.

HORN
H-137

ELECTRICAL
COMPONENT
REPLACEMENT
H-150

WINDSHIPLD
WIPER SYSTEM
H-141
thru
149

SERVICE
DIAGNOSIS.
. .H-151

ELECTRICAL
SPECIFICATIONS
H-152

Caution:
When installing the battery, the nega­
tive terminal must be grounded. Reverse polarity of the battery can cause severe damage to the charg­ing system.

Battery
Inspection

a.
Check
the specific gravity of the electrolyte in
each cell of the battery. A hydrometer reading of 1.260 indicates that the battery is fully charged.

If
the reading is 1.225 or below, the battery
needs

recharging.
If one or more cells is 25 "points" (.025) or more lower than the other cells, this in­
dicates that the cell is shorted, the cell is about to

fail,
or there is a
crack
in the battery partition in
the case. Unless the battery is repaired or replaced, battery trouble
will
soon
be experienced.

b.
Check
the electrolyte level in each cell, add

distilled
water to maintain the solution [9,5 mm.] above the plates. Avoid overfilling. Replace
the filler caps and tighten securely. It is important to keep the electrolyte level above the plates at all
times because plates that are
exposed
for any
length of time
will
be seriously damaged.

c.
Check
the wing nuts on the hold-down frame for tightness. Tighten them only with finger pres­

sure,
never with pliers or a wrench. Excessive
pressure
could damage the battery case.

d.
Clean
the battery terminals and cable con­ nectors. Prepare a strong solution of baking soda

and
water and brush it around the terminals to
remove any corrosion that is present. The cell caps must be tight and their vents sealed to prevent
cleaning solution entering the cells. After cleaning,
connect cables to battery and coat the terminals

with
heavy grease.

e.
Inspect the battery cables and replace if badly
corroded
or frayed.
Check
tightness
of terminal
screws to ensure
good
electrical connections.
Check

the
tightness
of the negative ground cable con­nection at the frame to ensure a
good
ground
connection.
f.
Load
test
the battery. Connect a voltmeter across the battery. Run the starting motor for 15 seconds. If the
voltage
does
not drop below 10
volts the battery is satisfactory. If the
voltage
falls
below the figure given, yet the specific gravity is
above
1.225,
the condition of the battery is questionable.
g. Be sure the
engine
ground strap connection, 172

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

H

FIG.
H-l—ENGINE
GROUND
STRAP—F4
ENGINE
Fig.
H-l, is tight at both connections. If
these

connections are
loose
-
or
dirty,
hard
starting or
failure
to start may result.

H-3.
Ignition System

The
ignition system consists of the battery, ignition

switch,
ignition coil ballast resistor (V-6 engine
only),
ignition coil, ignition distributor,
spark
plugs,

and
the low and high tension wiring.
Electrical

energy is obtained from the battery while cranking
and
from the alternator after the engine is running.

These
supply circuits must be considered part of
the ignition system.

The
ignition system furnishes the
spark
-for the

spark
plugs. The
spark
must occur in each cylinder
at exactly the proper time. To accomplish this, the following units are required.

a.
The battery, supplying the electrical energy.
Note: 'Jeep* vehicles equipped with Dauntless

V-6
engines have a ballast resistor connected be­ tween the ignition switch and the positive (+)

terminal
of the coil. The ballast resistor limits to
a
safe maximum the
primary
current flow through
the coil and the distributor contact points.

b.
The ignition coil, transforming the battery low
tension current to high tension current that jumps
the
spark
plug gap in the cylinders under com­
pression.

c.
The distributor, delivering the
spark
to the

proper
cylinders and incorporates the mechanical

breaker,
that
opens
and closes the
primary
circuit at the exact time.

d.
The
spark
plugs, providing the gap in the engine
cylinders.

e. The wiring, connecting the various ignition
units.

f. The ignition switch controling the battery
current
when it is desired to start or
stop
the engine.
g. The firing order for the
Hurricane
F4 engine is
1-3-4-2.
Cylinder
No. 1 is the cylinder closest to the

radiator.

h.
The firing order for the Dauntless V-6 engine
is
1-6-5-4-3-2.
Cylinders
1-3-5 are on the left bank

and
cylinders 2-4-6 are on the right bank. H-4.
PRIMARY
CIRCUIT

Before testing the
primary
circuit,
make certain
that the battery is satisfactory or install a fully

charged
battery for the
primary
circuit
tests. Also,

check
the starter motor for excessive voltage drop

and
check the starter motor itself for excessive
draw.

a.
Measure the voltage at the coil
primary
termi­

nals
while cranking the engine with the starter
motor. If the voltage is less than 9 volts the trouble

will
be found in the
primary
circuit.
If there is no voltage at all, check for a break in the
primary

circuit,
possibly in the coil
primary
winding.

b.
To check the
primary
circuit,
turn
the ignition
on,
turn
the engine until the points are closed, and
then measure the voltage drop across each portion
of the circuit with a voltmeter.
Note: Most voltage drops
will
be found at the con­
nections of wires to terminals as
dirt,
oxidation etc. can cause excessive resistance at
these
points.

Measure
voltage drops in wires to take this into
account.

c.
Connect the voltmeter from the battery cable

terminal
on the starter solenoid to the battery

terminal
of the coil
primary.
If the voltmeter reads more than 0.2 volt, perform the checks given in
steps, d, e, and f following.

d.
Connect the voltmeter from the solenoid termi­

nal
to the battery terminal of the ignition switch.
If
the voltmeter reads more than .05 volt, check

and
clean the connections at solenoid, light switch,
and
ignition switch.
e. If the voltmeter reading in
step
d is less than .05 volt, connect the voltmeter from the battery

terminal
to the ignition terminal on the ignition
switch.
If the voltage drop is more than 0.1 volt,

repair
or replace the ignition switch.
f. If the voltage drop in
step
e is not more than 0.1 volt, connect the voltmeter from the ignition

terminal
of the ignition switch to the battery termi­

nal
of the coil
primary.
If the voltmeter reads more

than
.05 volt, clean and tighten the connections

and
check again. If the voltmeter again reads more

than
.05 volt, replace the wire.
g. Connect the voltmeter from the distributor
primary
terminal on the coil to the coil terminal on
the distributor. Voltage drop should not exceed .05 volt.
Clean
and tighten connections if necessary.

h.
Connect the voltmeter from the coil terminal
on the distributor to a clean,
paint-
free spot on the

distributor
body. The reading should not exceed .05
volt. If more, it indicates excessive resistance
through the points or in the distributor internal connections.
Clean
and align the points and make

sure
the breaker arm connection to the
primary

terminal
as well as the stationary contact point mounting in the body is clean and tight.

i.
Open the points and check the voltmeter. It
should read close to peak voltage. Low voltage in­ dicates that a circuit through the distributor (a

short)
exists while the points are open.

j.
Disconnect the condenser lead and open the points. A jump to
full
voltage indicates a short in 173

H

ELECTRICAL
SYSTEM
the condenser. Replace the condenser. If there is
no jump to full voltage, overhaul or replace the

distributor.

k.
With the points closed, connect the voltmeter

from
a clean, paint-free
post
on the distributor
body to the negative
post
of the battery. The volt­
age drop should be practically zero, a hardly
readable deflection on the voltmeter. If the volt­ meter registers a
voltage
drop, perform the checks

in
steps
1
and m following.

I.
Check
for
voltage
drop in the battery ground
cable.
Clean
the battery
post,
cable terminals, and contact surface on the bellhousing, or on body if

a
noticeable deflection of the voltmeter occurs,
m.
Check
for any
voltage
drop
between
the dis­

tributor
body and a clean, paint-free
spot
on the

cylinder
block. If there is any
voltage
drop, remove
the distributor and clean the mounting surfaces of
distributor
body and cylinder block.

H-5.
SECONDARY
CIRCUIT
If
satisfactory ignition is not obtainable with cor­

rect
point gap and tension; satisfactory condenser;
sufficient primary voltage; and correctly cleaned, gapped, and installed spark plugs; the secondary

circiut
should be investigated.

a.
Test the coil.
Bring
the coil up to operating
temperature using the coil heat feature of a coil tester, if available. Refer to the coil tester manu­

facturer's
instructions for specific hook-ups for
performing the checks given in
steps
b, c, and d following.
b. Connect the positive lead of the tester to the
battery terminal of the coil primary winding.
Con­
nect the tester ground lead to the coil tower. Mea­

sure
the resistance of the secondary winding. If the
resistance is more than
20,000
ohms, a fault in the
secondary winding is indicated.
c.
Check
for a grounded secondary by touching the tester ground lead to the coil cover. If resistance
is not over
100,000
ohms, the secondary is grounded
to the cover.

d.
If the secondary winding is satisfactory, mea­
sure
the primary current draw in accordance with
the instructions of the
test
equipment manu­
facturer.

e.
Check
the secondary circuit for leakage. With the coil primary in the circuit with the breaker unit of the tester, connect a long, high-tension
test
lead
to the coil tower.
Check
the secondary circuit for
leakage by performing the checks given in
steps
f. g, h, and i following.

Note:
In the following
tests,
a slight sparking and
meter deflection
will
usually be
seen
just as contact
is made.
This
is caused by capacitance and
does
not
indicate defective insulation.
f.
Check
distributor cap. Remove the coil lead from the cap and touch the
test
lead to the center contact
inside the cap. If the meter reading drops when the contact is touched or if sparking is seen, a leakage
path is present
between
the center contact and one
of the plug towers.
This
leakage path
will
be in the

form
of a
crack
or carbon track in the cap. Discon­ nect the spark plug wires from the cap one at a
time and
test
each plug contact with the high-
voltage
lead and with all other plug wires con­
nected. Any sparking or meter drop indicates that

a
leakage path exists
between
that particular con­
tact and an adjacent one. Testing the adjacent contacts
will
determine which pair is at fault,
g-
Check
distributor rotor. Touch the
test
lead to
the spring contact in the center of the distributor
rotor.
Any leakage in the rotor insulation
between

the contact and the shaft
will
cause a drop in the meter reading and usually sparking
will
be seen.

h.
Check
spark plug wires. Disconnect the spark
plug wires from the plugs and
test
the plug terminal of each. The meter reading should not drop below
the open secondary value (value before making contact). If it
does
or if a large spark occurs when
the
test
lead and the plug wire are separated, there
is a break in the insulation on that wire.

i.
Check
the coil tower insulation. Remove the
high-tension
test
lead from the coil tower and touch
the ground lead of the coil tester to several points

around
the base of the tower. Any sparking or deflection of the meter indicates a leakage path in
the tower insulation.

H-6.
Alternator Charging System

All
Jeep
Universal
Series vehicles have, as standard
equipment a 35-amp., 12-volt, negative ground
alternator and a transistorized
voltage
regulator.
For
repairing the alternator, many of its major components are furnished as complete assemblies

including:
complete brush assembly which requires no soldering or unsoldering of leads; two complete
rectifying
diode
assemblies which eliminate the need for removing and replacing individual diodes;

a
complete isolation
diode
assembly; and a rotor assembly complete with shaft,
pole
pieces, field coil,

and
slip rings.

The
transistorized
voltage
regulator is an electronic
switching device. It
senses
the
voltage
appearing at the auxiliary terminal of the alternator and
supplies the necessary field current for maintaining the system
voltage
at the output
terminal.
The out­
put current is determined by the battery electrical

load;
such as headlights, heater, etc.
The
transistorized
voltage
regulator is a sealed unit,
has no adjustments, and must be replaced as a
complete unit.

H-7.
Starting System

The
operation of the starter motor is controlled by
the ignition switch. The starter is made up of a
frame,
field coil, armature, and brushes.

The
starter solenoid electrically
closes
the circuit

between
the battery and the starter motor. When the ignition key is turned to its extreme right, the
solenoid is energized and
closes
the battery-to- starter-motor circuit.

Note:
All Jeep Universal Series vehicles have the

starter
solenoid switch secured to the starter motor
assembly. The Hurricane F4 and Dauntless V-6

engine
Prestolite starter drive is of the inertia type
(rexr
continued on
page
176) 174

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

H

12967
FIG.
H-6—WIRING
DIAGRAM—LATE
V6
ENGINE

1—Left Headlamp

2—
Left
Parking and Signal Lamp
3—
Right
Parking and Signal Lamp

4—
Right
Headlamp
5— Voltage Regulator
6—
Alternator
7—
Oil
Pressure
Sender

8— Temperature
Sender

9—
Ignition
Distributor
10— Junction Block

11—
Horn

12—
Ignition
Coil

13— Starting Motor
14— Battery Ground Cable 15— Foot Dimmer Switch 21-
16— Stop
Light
Switch — Front 22-
17— Ballast 23-
18—
Flasher
(Directional Signal) 24-
19—
Fuse
25-
20— Instrument Cluster 26-

A—Hi-Beam
Indicator 27-

B—Auxiliary
28- C—Instrument Lights 29-

D—Oil
Pressure
Indicator 30-
E—Charging Indicator 31-F—Temperature Indicator 32-
G—Fuel
Gauge
33-
H—Instrument Voltage Regulator 34-
-Ignition
and
Starter
Switch

-Horn
Button

-Directional
Signal Switch
-4-Way
Flasher
Switch

-Flasher
(4-Way)

-Fuse

-Main
Light
Switch
-Stop
Light
Switch —
Rear

-Fuel
Gauge
Tank
Unit

-Back-Up
Light
Switch

-Right
Tail
and Stop Lamp

-Right
Back-Up Lamp

-Left
Back-Up Lamp

-Left
Tail
and Stop Lamp
be burned on the horizontal
face
and the cap will

also
need
replacing. H-12. Condenser

The
condenser
prolongs
the
life
of the distributor

points
by
preventing
arcing at the
contacts.
It
also
provides
a
hotter
spark by creating a reverse
surge

of current which rapidly breaks
down
the
magnetic

field of the coil by
demagnetizing
the core. Should
the
condenser
be leaky, a weak spark will result.

Check
the
condenser
lead for broken wires or
frayed insulation. Clean and
tighten
the
connec-
179

H

ELECTRICAL
SYSTEM

ffKHs)

3—<§)

FIG.
H-7—WIRING
DIAGRAM—V6
ENGINE
CURRENT
MODEL
1—
Left
Headlamp
2—Left Parking and Signal Lamp
3— Right Parking and Signal Lamp
4—Right Headlamp 5—
Marker
Lamp — Amber
6— Alternator 7— Voltage Regulator
8— Starting Motor
9— Battery Ground Cable
10— 12 Volt Battery
11—
Flasher
(Directional Signal)
12— Instrument Cluster
A—Hi-Beam
Indicator
B—Auxiliary

C—Instrument
Lights

D—Oil
Pressure Indicator
E—Charging
Indicator

F—Temperature
Indicator

G—Fuel
Gauge Indicator
H—Instrument Voltage Regulator
13— Ignition and Starter Switch
14—
Horn
Button
15— Directional Signal Switch
16— 4-Way Flasher Switch 17—
Flasher
(4-Way)
18— Windshield Wiper Motor Switch
19—
Main
Light Switch
20—
Fuel
Gauge
Tank
Unit
21—
Back-Up
Light Switch
22—
Marker
Lamp — Red
23— Right
Tail
and
Stop
Light 24— Right Back-Up Lamp
25—
Left
Back-Up Lamp 26—
Left
Tail
and
Stop
Light
27—
Marker
Lamp — Red
28—
Stop
Light Switch
29— Foot Dimmer Switch
30— Windshield Wiper Motor Assembly
31—
Ballast
Resistor 32— Ignition
Coil

33—
Spark
Plugs and Cables 34— Temperature Sending Unit
35—
Oil
Pressure Sending Unit 36—
Horn
37— Junction Block
38—
Marker
Lamp — Amber

lions
on the terminal
posts.
Be sure
condenser
is
mounted
firmly on the distributor for a
good
ground
connection.

Should a
condenser
tester
be available the capacity for
both
F4 and Prestolite V6
condenser
should
check from .25 to .28 microfarads. In the
absence

of
tester,
check by substituting a new
condenser.

H-13. Distributor Points
a. Examine the distributor
points.
If
they
show

wear,
poor
mating, transferred metal, or pitting,

then
new
ones
should be installed. Clean the
points

with a suitable
solvent
and a stiff bristled brush.
b. Check the
alignment
of the
point
for a full,
square
contact.
If not correctly aligned, bend the
stationary
contact
bracket slightly to provide align­
ment.

c. The
contact
gap should be set at .020"
[0,508
mm.],
on the F4 and .016"
[0,406
mm.] on the
Prestolite V6. Adjustment of the gap is accom­ plished by
loosening
the lock screw and turning adjusting eccentric screw until correct gap is
secured. Be sure that the fiber block on the breaker

arm
is resting on the
highest
point
on the cam while the adjustment is
being
made. Recheck the gap
after locking the adjustment.
d. Apply a thin film of cam lubricant to the cam to
lessen
fiber block wear.
e. Using Tool C-4094, check
point
contact
spring
pressure, which should be
between
17 and 20

ounces
[0,487
a
0,567
kg.] on the F4 and 17 to 22 oz.
[0,487
a
0,624
kg.] on the Prestolite V6.

Check
with a spring scale
hooked
on the breaker

arm
at the
contact
and pull at right
angle
to the
breaker arm. Make the reading just as the
points

separate. Adjust the
point
pressure by
loosening
the stud holding the end of the
contact
arm spring
and slide the end of the spring in or out as
neces­

sary.
Retighten the stud and recheck the pressure. Too low a- pressure will
cause
engine
missing at
high
speeds.
Too high a pressure will
cause
rapid
wear of the cam, block, and
points.
180

H

ELECTRICAL
SYSTEM H-61.
Test Nine

Operate
at a medium speed with the jumper re­ moved. Remove the regulator cover and hold the

voltage
regulator contacts closed.

a.
Voltage builds up—voltage regulator contacts
burned
or dirty or incorrect regulator setting.

Clean
the contacts and adjust the regulator as in

Par.
H-47d.

b.
Voltage
does
not build up—clean contacts and
repeat
test.
If the
voltage
still
does
not build up, see
test
10.

H-62.
Test Ten
Remove the regulator cover and hold the current
regulator contacts closed.

a.
Voltage builds up—current regulator contacts
burned
or dirty or incorrect regulator setting.

Clean
the contacts and adjust the regulator as in

Par.
H-47d.

b.
Voltage
does
not build up—clean the contacts

and
repeat the
test.
If the
voltage
still
does
not

build
up remove the regulator for an overhaul.

H-63. ALTERNATOR CHARGING SYSTEM

Most vehicles have, as standard equipment, a 35-

amp.,
12-volt, negative ground alternator and a
transistorized
voltage
regulator.
The
alternator charging circuit consists of the
battery, alternator,
voltage
regulator, ignition
switch,
and charge indicator light.

An
alternator differs from a conventional DC
shunt generator in that the armature is stationary,

and
is called the stator, while the field rotates,
and
is called the rotor.
With
the alternator con­
struction,
the higher current values involved in
the stator may be conducted to the external circuit through fixed leads and connections, rather than
through a rotating commutator and brushes, as in the DC generator.

The
alternator employs a three-phase stator
winding. The rotor consists of a field coil encased
between
six poled interleaved sections, producing

a
twelve
pole
magnetic field with alternator north

and
south poles. By rotating the rotor inside the stator, an alternating current is induced in the stator windings.
This
alternating current is
changed to direct current by
diodes
and conducted
to the output terminal of the alternator.
Six
silicon
diode
rectifiers act as electrical one-way valves.
Three
of the
diodes
have negative polarity

and
are grounded. The other three
diodes
have
positive polarity and connected to the output
terminal.
In all alternators discussed in this

manual,
the
diodes
are pressed into heat sinks.

There
are two heat sinks, one positive and the
other negative.

Since
the
diodes
have a high resistance to the
flow of
current
in one direction and a low resistance
in
the
opposite
direction, they are connected in a
manner
which allows current to flow from the
alternator to the battery in the low resistance
direction.
The high resistance in the
opposite

direction prevents the flow of current from the
battery to the alternator. Because of this feature,
no
circuit
breaker
is
required
between
the alternator
and
the battery.
Residual
magnetism in the rotor field
poles
is
negligible. Therefore the starting field current must be supplied by the battery. It is connected
to the field winding through the ignition switch

and
charge indicator lamp.
As
in the DC shunt generator, the alternator
voltage
is regulated by varying the field current.
In
these
alternator systems, this is accomplished
electronically in the transistorized
voltage
reg­
ulator.
No current regulator is required since all
alternators have self-limiting current character­
istics.

The
entire DC output of the alternator has to pass
through the isolation diode. The isolation
diode
is
not essential for rectification. Its purpose is threefold.
It
provides automatic solid
state
switch for
illumi­

nating the alternator charge
-
discharge indicator
light when the alternator is not charging properly.
It
automatically connects the
voltage
regulator to
the alternator and battery when the alternator is
operating.
It
eliminates electrical leakage across the alternator

diodes
so that leakage is negligible when the vehicle
is not in use.
The
isolation
diode
is mounted in a separate alumi­

num
heat sink. The 35-amp. alternator has a single
silicon diode. The alternator is designed to supply the electrical demands of the battery and the
accessory circuits through a wide range of
engine

speeds. The alternator is lighter and more compact

than
a conventional DC shunt generator of com­

parable
electrical size.

The
principal
components of the alternator are
the stator, the rotor, the slip ring end head, the

drive
end head, the
diode
rectifiers, and the isolation diode.

a.
The stator consists of a laminated iron core on

which
the three-phase windings are wound in
slots
around
the inside circumference. A
pair
of leads
are
connected to each of the three points of the
winding. One of each
pair
of leads connects to a
negative
diode
rectifier and one to a positive
diode
rectifier.

b.
The rotor consists of a single field coil encased

between
two six-fingered, interleaved iron sections assembled to the shaft. The two ends of the field
coil
are connected to two slip rings which are in­
sulated from each other and from the shaft.
c. The slip ring end head supports the rectifier heat sinks; a prelubricated sealed
ball
bearing, in

which
the rotor shaft rotates; and the brush holders
and
brushes.

d.
The drive end head supports a prelubricated
sealed
ball
bearing in which the drive end of the rotor shaft rotates.
e. The
diode
rectifiers are pressed in the rectifier brackets or heat sinks and are connected to the
stator leads.
f. The isolation
diode
is pressed in the aluminum heat sink mounted to the
rear
of the alternator. The
complete assembly is covered with a red insulating coating.

For
repairing the alternator, many of its major components are furnished as complete assemblies

including:
complete brush assembly which requires 194

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL

H
no soldering or unsoldering of leads; two complete

rectifying
diode assemblies
which
eliminate the need
for removing and replacing individual diodes; a
corpplete isolation diode assembly; and a rotor
assembly complete with shaft,
pole
pieces, field

coil,
and slip rings.

The
transistorized
voltage
regulator is an electronic
switching device. It
senses
the
voltage
appearing
at the auxiliary terminal of the alternator and
supplies the necessary field current for maintaining
the system
voltage
at the output terminal. The
output current is determined by the battery electri­
cal
load; such as headlights, heater, etc.

The
transistorized
voltage
regulator is a sealed

unit,
has no adjustments, and must be replaced
as a complete unit.

H-64. ALTERNATOR
PRECAUTIONS

The
following precautions must be observed to
prevent damage to the alternator and regulator.

a.
Never reverse battery connections. Always

check
the battery polarity with a voltmeter before

any
connections are made to be sure that all con­
nections correspond to the battery ground polarity of the vehicle.

b.
Booster batteries for starting must be properly
connected. Make sure that the negative cable of
the booster battery is connected to the negative

terminal
of the battery in the vehicle. The positive
cable of the booster battery should be connected
to the positive terminal of the battery in the
vehicle.

c.
Disconnect the battery cables before using a fast charger.

d.
Never use a fast charger as a booster for

starting
the vehicle.

e.
Never disconnect the
voltage
regulator while
the
engine
is running.

f.
Do not ground the alternator output terminal.
g.
Do not operate the alternator on an open
circuit
with
the field energized.

h.
Do not attempt to polarize an alternator.

These
precautions are stated here as an aid to

service
personnel. They are also restated at appro­

priate
places in the
text
of this section of the
manual.

H-65. ALTERNATOR
CHARGING
SYSTEM SERVICE
Important:
All alternator
tests
for the 35, 40 and
55 amp alternator are the same, however, there is a
difference
between
the location of the various ter­

minals
and field current specifications. The field

current
of the 35 amp alternator should be 1.7 to 2.3 amps, 40 and 55 amp alternators should be 1.8
to 2.4 amps, with
full
battery
voltage
applied to
the filed coil. Disassembly and assembly procedures

are
the same for all three alternators.
Terminal
locations and wire harness color
codes
for the 35,
40 and 55 amp alternator are shown in Fig. H-38.

H-66.
Service Diagnosis

In
diagnosing a suspected malfunction of the

alternator
charging system, consideration must
be given to the complete electrical power plant of the vehicle; including the alternator, regulator,
ignition switch, charge indicator lamp, battery,

and
all associated wiring. If it is suspected that the

alternator
is not fully charging the battery and

fulfilling
the electrical requirements of the electrical
system, several checks should be made before

checking
the alternator itself:

Note:
Whenever service is required in connection

with
an alternator problem, the first
step
should be to verify that the wiring harness hook-up is correct
as indicated in Fig. H-38.

a.
Test the condition of the battery and
state
of
charge
(Par. H-2).
If the battery is not fully charged
and
in
good
condition, use a replacement battery
for making alternator system
tests.

Caution:
Make certain that the negative battery

post
is connected to ground when making the
battery installation. Serious damage to the alter­

nator
can result if battery polarity is reversed.

b.
Check
fan belt for proper tension (Par.
C-27).

Caution:
To increase belt tension, apply pressure
to alternator front housing only as permanent damage can result if pressure is applied to
rear

housing.

H-67.
Alternator In Vehicle Tests

The
following
tests
are made with the alternator

in
the vehicle with output and regulator connec­
tions maintained to the alternator except as noted

in
Fig. H-27 and H-28. The field plug and
voltage
regulator are disconnected for
these
tests.
The

tests
are given in proper order and detail in the
following paragraphs.

a.
Isolation Diode Test: To determine if the isola­
tion diode is open or shorted, refer to Par. H-69.

b.
Alternator Output Test: To isolate the trouble
to the alternator or regulator, refer to Par. H-70.

c.
Alternator
Field
Circuit
Test: To determine the condition of the field
circuit
(brushes and rotor),

refer
to Par. H-73.

d.
Brush
Insulation
and Continuity
Test:
To deter­
mine the condition of the
brush,
refer to
Par.
H-75.

e.
Rotor In-Vehicle Test: To determine whether
the rotor coil is open or shorted, refer to
Par.
H-73.
f. Any further
tests
must be conducted with the

alternator
removed and disassembled. When this
is done, the condition of the rotor, the rectifying

and
isolation diodes, and the stator can be further
tested.

A
commercial alternator tester Sun
Electric
Model

VAT-20
or equivalent can be used to make all
necessary
tests
on the alternator system. If a com­

mercial
tester is used, follow the recommended
testing procedure outlined by the tester manu­

facturer.
If
a commercial tester is not available, follow the
testing procedure as outlined in this manual.

H-68.
Test Equipment

a.
Volt Ampere Tester such as Sun
Electric
Model

VAT-20
or equivalent with meter ranges as shown

in
the following list can be used. 195