alternator JEEP CJ 1953 Owner's Manual

'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

H

ELECTRICAL
SYSTEM DC
ammeter — 0 to 60 ampere

DC
ammeter — 0 to 5 ampere

DC
voltmeter — 0 to 16 volt
Rheostat — 40 ohm capable of
handling
3 amps.

Carbon
Pile — 45 amperes

b.
Diode Rectifier Tester C-3829.

c.
12-volt DC
test
lamp.

d.
Ohmmeter of any commercial type is not ab­solutely necessary but can be helpful.

H-69.
Isolation Diode
Check

With
the ignition key in the off position the correct voltage at the auxiliary terminal is zero volts. If
voltage measured at auxiliary terminal is the same as voltage at output terminal, the isolation diode
is shorted. In most cases, the charge indicator lamp
would be glowing with the ignition off if the isola­ tion diode were shorted. Refer to Fig. H-23.
GREEN

DC
VOLTS
13401

FIG.
H-23—ISOLATION DIODE
TEST-
SHORTED DIODE
With
the engine running the correct voltage at the

auxiliary
terminal is 15.4 volts and at output ter­

minal
is 14.4 volts. If voltage of auxiliary terminal
is 15.4 volts, while at output terminal it is 12 volts

or
battery voltage, the isolation diode is open. In
most cases, this would be indicated by the charge

GREEN

TO
CHARGE
INDICATOR
LAMP1

15.4
VOLTS BLACK
VOLT

REG DC
VOLTS

BATTERY

DC
VOLTS
FIG.
H-24—ISOLATION DIODE
TEST-

OPEN DIODE
indicator
lamp glowing when the engine is running.

Refer
to Fig. H-24.

If
the isolation diode is shorted or open, the heat

sink
and diode should be replaced as an assembly.

At
the time of manufacture, the diode is pressed into the heat sink and the complete assembly is in­
sulated from the alternator housing.

H-70.
Alternator Output Test

This
test
excludes the regulator from the alternator
system, thereby isolating the problem to either the regulator or alternator. Disconnect field and voltage regulator plug and
connect jumper from auxiliary terminal to field

terminal.
Start
engine and run at idle. Refer to

Fig.
H-25.
DC
VOLTS

13403

FIG.
H-25—ALTERNATOR OUTPUT
TEST
If
voltage at auxiliary terminal rises to 15 or 16
volts now, when it did not with voltage regulator
connected, then defect is in regulator and it should
be replaced. If voltage
does
not rise at auxiliary

terminal,
defect is in alternator stator or rectifier diodes, if field circuit checked out properly. For
defects
in stator or diodes, remove alternator from vehicle.

If
rated current output is obtained with at least 13
volts but less than 15 volts at the output terminal,
the alternator is functioning properly.

Caution:
Do not exceed rated current output of
alternator
by increasing load on alternator.

If
rated
current
output cannot be obtained, proceed

with
the
tests
and checks given in the following
paragraphs
and isolate the cause.
Note: The system is designed to produce slightly
more output at low operating temperatures and less
at higher temperatures to accommodate the
varying
demands of electrical power normally consumed at

these
temperatures.

H-71.
Regulator Test

The
regulator should be checked with an alternator
that is functioning properly. If the alternator is questionable, perform the Alternator Output Test
(Par
H-70) which excludes the regulator from the

charging
system and, therefore,
tests
the condition
of the alternator alone. 196

'Jeep'
UNIVERSAL SERIES SERVICE
MANUAL

H
H-72.
Removal
and
Installation
of

Voltage Regulator

The
transistorized
voltage
regulator is a sealed unit.
It
cannot be disassembled or adjusted. If found to
be defective in any way, it must be replaced as
a
unit.

The
transistorized
voltage
regulator is mounted on
the fender dust shield by three mounting screws.

Wiring
connections to the charging circuit are made through a three-prong connector.

To
remove the regulator, disconnect the three
-
prong connector and remove the three mounting

screws.
Installation of the regulator is the reverse
of the removal. (Refer to Fig. H-26.)
FIG.
H-26—VOLTAGE
REGULATOR

H-73.
Alternator Field Circuit Test

Voltage
Test — Refer to Fig. H-27.

a.
With the ignition key on and
engine
not
run­
ning,
the correct
voltage
at the auxiliary terminal is
approximately 1.5 volts. If the
voltage
at auxiliary

terminal
is higher than 2 volts, field circuit is defective — check brushes.
GREEN

13404

FIG.
H-27—FIELD
CIRCUIT TEST—VOLTAGE If
voltage
reads zero volts at auxiliary terminal,
check charge indicator lamp and associated circuit.
If
this
voltage
is not correct, continue with the fol­
lowing
test
described in paragraph b.
Amperage Test — Refer to Fig. H-28. b.
This
test
evaluates complete field circuit, inde­
pendent of
voltage
regulator.
Circuit
is through
brushes, slip rings, rotor to ground. With ignition switch off, current should be 2 to 2.5 amps. If
less

than
this, check brushes and slip rings. It is de­

sirable
to use a field rheostat in series with meter
for protection of the meter. If field is shorted, ex­
cessive current
will
flow through meter and dam­
age may result.
GREEN
FIELD
WIRE

DISCONNECTED

13405

FIG.
H-28—FIELD
CIRCUIT TEST- AMPERAGE
DRAW
H-74.
Brush Removal
and
Inspection

Refer
to Fig. H-29.

The
brushes can be removed and inspected while
the alternator is in the vehicle.

a.
Disconnect the plug to the field terminal. b. Remove the two screws and brush cover.
c. Remove brushes.
d.
Inspect brushes for excessive wear and proper
tension. The brushes can be installed by reversing
the above procedure.

H-75.
Brush Insulation
and
Continuity Test

Refer
to Fig. H-30.

a.
Connect leads of a 12-volt
test
lamp to field
FIG.
H-29—BRUSH
REMOVAL

1—
Screw

2—
Cover

3—
Brush
and
Holder
Assembly
4—
Alternator
197

H

ELECTRICAL
SYSTEM
terminal
and bracket. Test lamp should not light.

If
it
does,
the
brush
is shorted and must be replaced,
b.
Connect one lead of an ohmmeter to field ter­

minal
and the other lead to insulated brush. Re­
sistance reading should be zero. Move brush and

brush
lead wire to make certain that the brush lead wire connections are not intermittent. Resist­
ance reading should not vary when brush and lead

wire
are being moved.

C.
Connect ohmmeter leads to bracket and grounded brush. Resistance reading should be zero.
Repeat same
test
on brush lead wire as described

in
step
b above.
FIG.
H-30—INSULATION
AND
CONTINUITY

TEST
POINTS
1^-Brackct

2—
Field
Terminal

3—
Grounded
Brush

4—
Insulated
Brush

H-76.
Rotor
In-Vehicle
Tests

a.
Reference Par. H-73, Fig. H-28.
b.
To check for a short circuit in the rotor wind­
ings, the alternator should be removed. Refer to

Par.
H-79 for rotor bench
tests.

H-77.
ALTERNATOR
BENCH
TESTS

When
the various
tests
given in
Par.
H-69 through
H-76 have determined a fault within the alternator itself, the alternator should be removed from the vehicle and the following
tests
given in
sequence

to isolate the trouble to a particular
component

of the alternator.
Note
that certain
tests
can be
performed after the alternator is removed and
before
it is disassembled.

H-78.
ALTERNATOR
REMOVAL
Note:
Brushes and isolation
diode
can be removed

from
alternator without removing unit from vehicle.

a.
Disconnect all lead connections at alternator.
b.
Remove nut and
bolt
at alternator support

bracket.
Remove nut, bolt, washer, and adjustment

bracket.
Remove belt from alternator pulley. The alternator is now free to be removed from the
vehicle.

H-79.
Rotor Tests
—
Bench

This
test
checks the condition of the rotor (field coil) for
open
or shorted field winding, excessively

worn
or sticky brushes, and
open
connections. It should be performed with the brush assembly in­
stalled in the alternator.

a.
The field coil is checked for a short circuit
by connecting a fully charged battery and an ammeter in series with the two slip rings.

A
rheostat is placed in series in the
circuit
to protect
the instruments and
components
of the alternator. Set rheostat to maximum resistance (40 ohms)

before
making connections.

b.
Slowly reduce resistance of rheostat to zero.

Then
take reading on ammeter. With full battery
voltage
applied to the field coil, the field current
of the 35-amp. alternator should be 1.7 to 2.3 amp.

Note:
The field current of the 40 and 55 amp.
alternator should be 1.8 to 2.4 amps with full battery
voltage
applied to the field coil.
c.
Turn
rotor by hand, noting reading. Rotating
rotor
will
indicate if brushes are making
good
elec­

trical
contact. A slight fluctuation of reading (0.2

amp.)
is to be expected.
If
field current is not within limits, inspect brushes

and
slip rings for
excessive
dirt, sticky, or broken
brushes, and bad connections.
Check
brush as­ sembly for short and continuity (Par. H-75). Make
same
test
to slip rings. Reinstall repaired or known
good
brush assembly and repeat
test.
If
the field current is
above
the maximum value
specified, it indicates that the field coil is either
shorted to rotor or field coil has shorted windings.
If
the field current is zero, it indicates that the field

coil
or coil-to-slip ring connection is open. If the field
current
is considerably
less
than the value
specified, it indicates a poor coil-to-slip ring con­ nection or poor brush-to-slip ring connection.

d.
To check continuity of the rotor, disconnect the
battery and connect an ohmmeter directly across
the field. Resistance
between
field terminal and ground terminal should be approximately 6 ohms.
If
resistance is high, field coil is shorted.

e.
If rotor is found to be
defective
in
above
tests,
repeat the
above
tests
when the rotor is removed

from
the alternator by connecting the
test
circuit
to rotor slip rings to ascertain findings.
Field
current

will
be approximately 0.2 amp. higher than the
maximum
value because of the normal brush-to-

slip-ring
contact resistance that reduces field
current
slightly. If the rotor is found to be de­
fective, it should be replaced.

H-80.
Alternator Disassembly

Refer
to Fig. H-31.

a.
Remove brush assembly by removing two tap­ ping screws and cover. Then pull the brush as- 198

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

H

©
© © ® (a
1—
Bolt

2— Cap
Screw

3—
Brush
Assembly
Cover

4—
Brush
Assembly
5—
Locknut

6—
Isolation
Diode 7— Nut
8—
Insulated
Washer
9—
Rear
Housing

10—Slip
Ring
FIG.
H-31—ALTERNATOR

11—
Insulated
Washer 12— Negative Diode Assembly
13—
Positive Diode Assembly
14—
Stator

15—
Rear
Bearing 16—
Rotor
17—
Retaining
Clip

18—
Front
Bearing
19—
Front
Housing
20— Nut 11485
21—
Fan
22—
Pulley

23—
Lock
Washer
24— Nut 25—
Woodruff
Key 26—
Bushing

27—
Insulated
Sleeve
28— Nut sembly straight out until the brushes are clear of

rotor
assembly.
Lift
the brush assembly out of the housing.

b.
Remove the isolation
diode
assembly by re­
moving nuts.

c.
Remove fan, pulley, lock
washer,
nut and spacer.
With
the nut removed, remove pulley using
Puller,

the other parts can then be removed easily from the

rotor
shaft. The spacer
will
not
come
off until the key is removed.

d.
Separate front housing from
rear
housing by
removing
bolts
and nuts.
Then
insert blade of
a
small screwdriver in the stator
slots
between
the
stator and the front housing. Wedge apart the
halves of the alternator.

Caution:
Take
care not to insert the screwdriver
blade deeper than J/f6" [0,16 cm.] below a stator.

Otherwise
damage to the stator windings may

result.
It may be necessary to apply pressure at

several
points around the stator to extract rotor

and
front housing as an assembly. Be careful not
to
burr
the stator core as this would make reas­ sembly difficult.

e.
Remove the two rectifying
diode
heat sink as­semblies and the stator as a complete unit from
the
rear
housing by removing nuts and locknuts.
Note
that the positive
diode
assembly is insulated

from
the alternator housing by insulated washers

and
insulated sleeves.
f. The
diode
and stator assemblies may now be
tested
as outlined in
Par.
H-83.
For
additional
test­
ing
(Pars.
H-84 and H-85) or to replace a
diode
heat
sink
assembly, unsolder the three soldered con­
nections at the
diodes
to separate heat sink from stator.

Caution:
When unsoldering the stator wires from
the rectifier
diode
assembly, provide a heat sink
to the
diode
terminal using a
pair
of long-nosed
pliers
to dissipate the heat away from the diodes.

g.
To remove the rotor assembly from the front
housing remove the woodruff key and split spring

washer
(bearing retainer).
FIG.
H-32—REMOVING
FRONT
BEARING

1—Front
Bearing Remover C-4068
h.
With
the woodruff key removed and the split

spring
washer
loose,
the rotor may be removed
from
the front housing by tapping the rotor shaft
on a
soft
wood surface.

i.
Remove the front and
rear
bearings from the

rotor
shaft by using Bearing Remover C-4068 for
the front bearing, as shown in
Fig.
H-32, and
Bear­
ing Remover C-3936 for the
rear
bearing, as shown

in Fig.
H-33.

H-81.
General
Inspection

a.
All parts should be wiped clean and visually inspected for wear, distortion, and signs of over­
heating or mechanical interference.

b.
Check
the bearings for roughness or excessive

clearance.
They should be replaced if found defective.

Note:
New bearings are prelubricated. Additional

lubrication
is not required. 199

H
ELECTRICAL
SYSTEM
|
lists
>

FIG.
H-33—REMOVING
REAR
BEARING

1—
Rear
Bearing

2—
Rear
Bearing
Remover C-3936
The
alternator end housing may be
wiped
clean

with
a
cloth
dampened in solvent if excessively
dirty
but should not be
buffed
as this
will
destroy
special treatment given to
inhibit
corrosion.

H-82.
Out-Of-Circuit
Rotor Test

Refer
to
Pars.
H-76 and H-79 for
tests
to be per­ formed on the rotor. If
these
tests
were not per­formed while the alternator was assembled, they

can
be performed with the alternator removed by following the procedure given in
these
paragraphs.

H-83.
Out-Of-Circuit
Stator Leakage Test Disassemble alternator and remove the rectifier
diode plates and stator as shown in Fig. H-34 as
an
assembly.
An
ohmmeter or 12-volt
test
lamp may be used,

a.
Connect one ohmmeter or
test
lamp probe to
one of the rectifier diode terminals and the other
to the stator as shown in Fig. H-34.
FIG.
H-34—STATOR
LEAKAGE
TEST
POINTS
1—
Stator

2—
Diode
Terminal
Resistance
reading should be infinite or
test
lamp
should not light. If resistance reading is not infinite

or
test
lamp lights, high leakage or a short exists between stator winding and stator. In either case,
the diode heat sinks should be separated from the
stator (Par. H-80) to ascertain whether the stator
should be replaced (Par. H-84).

H-84.
Stator
Coil
Leakage and
Continuity
Test

This
test
checks for shorts or leakage between
stator coil windings. To conduct the
test,
the wind­
ing junctions must be separated as shown in Fig.

H-35.
An ohmmeter or 12-volt
test
lamp may be used.
|
.11521 •

FIG.
H-35—STATOR
LEAKAGE
AND
CONTINUITY
TEST
POINTS 1—
Test
Point 3—Test Point 5—Test Point

2—
Test
Point 4—Test Point 6—Test Point

a.
Connect one of the ohmmeter or
test
lamp probes to
test
point 4 as shown in Fig. H-35.
Con­

nect the other
test
probe to
test
point 5 and then to

test
point 6. Resistance should be infinite or
test

lamp
should not light.

b.
Connect one
test
probe to point 1 and the other
to point 3 and then point 2. Resistance should be infinite or
test
lamp should not light.

In
either
test,
if the resistance reading is not infinite

or
the
test
lamp lights, high leakage or a short
exists between stator windings. Stator should be
replaced.

c.
Measure resistance of each winding in stator between
test
points 4 and 1, 5 and 3, and 6 and 2,
in Fig.
H-35. 200

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

H
Resistance
should be approximately 0.1 ohm.

An
extremely accurate instrument would be neces­
sary
to ascertain shorted turns.
Only
an open condi­
tion can be detected with a commercial ohmmeter.

If
the alternator has been disassembled because of
an
electrical malfunction, replace stator only after

all
components have been checked and found to
be satisfactory.

H-85.
Out-Of-Circuit
Rectifier Diode Test

With
the rectifier diode heat sinks disconnected
from
the stator assembly (Par. H-80), the diodes

can
be individually checked with the Diode Tester

C-3829.
FIG.
H-36—RECTIFIER
DIODE
TEST
POINTS

1— Diode Plate Stud

2—
Diode Terminals

Fig.
H-36 shows the
test
point location for either positive or negative diode.

Plug
Tester C-3829 into a 110-volt AC outlet.
Connect
alligator clip to diode plate stud, and the probe of the tester to each of the three diode ter­

minal's
test
points. Negative diodes
will
give a
negative deflection of the needle and positive
diodes
will
give a positive deflection. The meter

reading
should be the same for each of the diodes

and
should be 2 or over for a
good
diode. If a diode is faulty, replace the entire diode heat sink
assembly. H-86.
Assembling Alternator

Refer
to Fig. H-31.

a.
To install front bearing in front housing, press
the bearing into place on an arbor press using

Bearing
Installer C-3858. Position the split spring

washer
in the front bearing housing oh top of the bearing.

b.
Install
the
rear
bearing on the rotor shaft front
end using Bearing Installer C-3935 as shown in

Fig.
H-37.
FIG.
H-37—INSTALLING
REAR
ROTOR
BEARING

1—
Rear
Bearing Installer C-3935

2—
Rotor
Shaft
C.
Place the rotor assembly
into
position in the
front housing by tapping rotor shaft on a
soft

wood surface.

d.
Position diode assemblies and stator as a unit
into the
rear
housing. Make certain that insulator
washers and insulator
sleeves
are correctly posi­
tioned on the positive diode assembly.

e.
To assemble the subassembly halves of the
alternator
(front
housing and
rear
housing). Slide
the front housing over the stator.
Install
the bolts
and
nuts.
f. Position first the spacer, then the woodruff key
on the rotor shaft and slide on the fan.
Carefully

position the alternator in a vise with the clamps
of the vise held to the pulley. Position the pulley
so it is just starting to slide over the woodruff

key.
Press it into position by tightening nut with

a
wrench. When the pulley is properly positioned,
remove the nut, place the lock washer on the

rotor
shaft, and again replace the nut.

g.
Install
the isolation diode assembly and secure

with
locknuts.

h.
Install
the brush housing in position in the
rear

housing.
Install
the brush housing cover and the
tapping screws.

i.
Turn
the rotor by hand listening carefully to

make
certain there is no interference between the

rotor
and the stator winding.
H-87.
Alternator Installation

To
install the alternator, reverse the procedure 201