1953 JEEP DJ oil

H

ELECTRICAL
SYSTEM

11035

FIG.
H-40—PRESTOLITE STARTING MOTOR—F4 ENGINE 1— End
Plate

2—
Plug

3—
Thrust
Washer
4—
Brush
Plate Assembly 5— Screw
6—
—Lock
Washer
7—
Insulating
Washer
8—
Terminal

9—
Field
Coil
and Pole
Shoe
Set
10—
Frame

11—
Insulating
Washer

12—
Washer

13— Nut 14—
Lock
Washer

15—
Insulating
Bushing

16—
Pole
Shoe
Screw
17— Sleeve Bearing
18—
Drive
End Frame
19—
Intermediate Bearing

20—
Bendix
Drive

21—
Screw

22—
Lock
Washer

23—
Thrust
Washer

24— Key
25—
Armature

26—
Thru
Bolt

27—
Insulator

brush
and
pull
On
a line parallel with the side of
the
brush.
Take
the
reading
just as the spring leaves the
brush.
It is important that the brush spring
tension be kept within the limits specified at the end of this section. If the tension is too low, there

will
be a loss of efficiency from poor brush contact.
Too
great a tension
will
cause excessive brush and
commutator wear. To change the tension, twist the

spring
at the holder with long-nosed pliers,

c.
Worn
brushes should be replaced. Brushes that
are
soldered to the field coil should be unsoldered

and
the
loop
in the field coil lead should be opened.
Insert
the new brush pigtail to its
full
depth in the
loop. The new brush lead should be tightly clinched

in
the terminal and then soldered to make a strong, low-resistance connection.

H-99.
Commutator

Check
the commutator for wear and discoloration.
If
the commutator is rough or worn the armature should be removed and the commutator turned
down in a lathe. A discolored commutator should
be cleaned with carbon tetrachloride. Never use
emery cloth.

H-100.
Armature

Visually
inspect the armature for mechanical
defects
before checking for shorted or grounded
coils. Use a set of
test
probes for testing armature

circuits.
To
test
the armatures for grounds, touch
one point of the
test
probes to a commutator seg­
ment and touch the other point to the core or shaft. Do not touch the points to the bearing surface or
to the brush surface as the arc formed
will
burn

the smooth finish. If the lamp lights, the coil con­ nected to the commutator segment is grounded.
To
test
for shorted armature coils, a growler as
shown-in Fig. H-42 is necessary. The armature is placed against the core and a steel strip is held
on the armature. The growler is then energized 204

UNIVERSAL
SERIES
SERVICE
MANUAL

H

t
^

12956

FIG.
H-41—PRESTOLITE
STARTING
MOTOR—V-6
ENGINE

1—
End
Plate
2—
Oiling
Pad

3—
Thrust
Washer
4—
Brush
Plate Assembly 5—
Screw

6—
Lock
Washer 7—
Insulating
Washer
8—
Terminal

9—
Field
Coil
and Pole Shoe

10—Frame
11—
Insulating
Washer
12—
Washer

13— Nut
14
—Lockwasher

15—
Insulating
Bushing
16— Pole Shoe Screw
17—
Bearing,
Outer
18—
Drive
End
Frame
Pinion Housing
19— Intermediate Bearing Housing
20—
Lock
Washer 21—
Screw

22— Bendix Drive
23—
Thrust
Washer

24—Pin

25—
Armature

2 6—Commutator
27—
Thru
Bolt
28—
Insulator

29—
Bearing,
Intermediate
and
the armature rotated slowly by hand. If a
shorted coil is present, the steel strip
will
become
magnetized and
will
then vibrate.
H-101-
Field
Coils

Using
test
probes, check the field coils for both
ground and
open
circuits.

a.
To
test
for ground, place one probe on the motor frame or
pole
piece
and touch the other probe to the field coil terminals. If a ground is present, the
lamp
will
light.
b.
To
test
for
open
circuits, place the probes on
the field coil terminal and on an insulated brush.
If
the light,
does
not light, the coil is
open
circuited.
H-102.
Brush
Holder Inspection

Using
test
probes, touch the insulated brush holder with one probe and a convenient ground on the commutator end head with the other probe. If the
lamp lights, it indicates a grounded brush holder.
H-103.
Starting Motor Reassembly

Refer
to Fig. H-40 and H-41.

a.
When assembling absorbent bronze bearing
found in the end plate and drive end frame, always
use the proper arbor
designed
to
give
the proper
bearing fit. Soak the bearings in oil
before
assem­
bling in the bearing bore. Give the bearing
seats

a
light coating of oil.

Note:
At assembly, the outer pinion housing bear­
ing must be flush with the bearing bore on the inside of the housing; the intermediate bearing
must be flush with the bearing bore on the side
toward the armature.

b.
Brushes should be correctly installed and con­
nected as outlined in Par. H-98 in order to be sure
of proper starting motor efficiency.
c. Assemble the armature bearing plate and Bendix

Folo-Thru
Drive to the drive end frame.
Install
the two holding cap screws and lock washers. Tighten them securely. 205

H

ELECTRICAL
SYSTEM

FIG.
H-42—GROWLER
d.
Install
the armature in starter motor frame,
using care to align the four brushes and brush
springs on the commutator so that they are free to
move
and are square on the commutator.

e.
Install
the thrust washer on the shaft.
Lubricate

the plug and bearing in the end plate.
Install
the
end plate.
Install
the two through
bolts
and tighten securely.

f.
On Prestolite V6 starting motors, check pinion position by measuring from the centerline of the
pinion housing mounting bolt
holes
to the outside

edge
of the pinion.
Correct
measurement with the
Bendix
drive retracted is [19,05 mm.] to
%"
[22,23 mm.]; with drive extended, 1%"

[34,93
mm.] to 1^" [38,10]. Adjust by installing

thrust
washers just inside the commutator end
head or intermediate bearing as required. The
Bendix
drive retaining pin must not project
beyond the outside diameter of the pinion
sleeve.

H-104.
Bench Test

The
motor should first be checked to see that the
free running
voltage
and current are within specifi­ cations. To
test,
connect the motor to a battery,
ammeter and voltmeter. If the current is too high
check
the bearing alignment and end play to make

sure
there is no binding or interference. Using a

spring
scale and torque arm check the stall torque to see that the motor is producing its rated
crank­

ing power. The stall torque
will
be product of the

spring
scale reading and the length of the arm

in
feet.
If the torque is not up to specifications

check
the seating of the brushes on the commutator
and
the internal connection of the motor for high
resistance. The Bendix
Folo-Thru-Drive
should be checked for correct operation. The Bendix pinion
should be checked to see that it shifts when the motor is operated under no load.

H-105.
Bendix Folo-Thru Drive (Prestolite)
The
Bendix
Folo-Thru
Drive is designed to over­

come
premature demeshing of the drive pinion
from
the flywheel ring gear until a predetermined

engine
speed is reached. See Fig. H-43. No repairs or adjustments are possible on this

drive
and a
complete
new unit must be installed

if
trouble develops.

H-106.
Lubrication
of
Folo-Thru Drive
A
periodic cleaning and relubrication of the drive is advisable, the frequency of which
will
depend on
the type of service to which the vehicle is sub­
jected and the locale of operation.

a.
Remove the starting motor from the
engine
and take off the outboard housing. The pinion and

barrel
assembly
will
be in the demeshed position
on the screwshaft. Do not
move
it forward
until
after
that portion of the armature shaft ahead
of the pinion has been cleaned. If accidentally ro­
tated to the outer end of the screwshaft it
will

lock
in that position and cannot be forced back.

b.
Do not disassemble the drive for any reason.

c.
Do not dip or wash the drive in any cleaning solution.

d.
Do not remove the drive from the armature
shaft. Remove
excess
oil, grease or foreign matter
from
the armature shaft by wiping it with a clean cloth.
3
10859
FIG.
H-43—BENDIX
FOLO-THRU DRIVE

Dampen
the cloth with kerosene if necessary. A
light film of
SAE
10 oil may then be applied to the shaft.

e.
Now rotate the pinion and
barrel
assembly to the
fully
extended position, thereby exposing the screw­ shaft triple threads. Use a cloth dampened with
kerosene to wipe them clean. Do not use
gaso­
line
or any
commercial cleaner.
If the dirt is

thick
and gummy, apply the kerosene with a small

brush.
Tilt
the starting motor so that a small
amount
will
run under the control nut. Relubricate

with
a thin film of
SAE
10 oil. Use SAE 5 at ex­ tremely low temperatures.

f.
Reassemble the starting motor to the
engine
with the drive in the extended position.
Carefully
mesh the pinion with the flywheel ring gear before
tightening the starter motor mounting bolts. It may 206

H

ELECTRICAL
SYSTEM
sibility
of the cable shorting at the
engine
or frame.
Remove nut and lock washer securing the ignition

wire
to the solenoid
post
and remove the two screws and lock washers securing the solenoid to
the starter frame. Remove the switch,
b.
To install the solenoid switch reverse the re­

moval
procedure given above.

H-10S.
STARTING MOTOR
—
DELCO
DAUNTLESS
V-6
ENGINE

Refer
to Fig. H-45.

The
starting motor used on the Dauntless V-6 en­

gine
has an integral solenoid switch and enclosed
shift lever which first shifts the overrunning clutch
pinion into
engagement
with the ring gear on the
flywheel of the
engine
and then
closes
the electrical
circuit
to cause
engine
cranking. When the
engine

starts,
the overrunning clutch
disengages
to pre­ vent transfer of
engine
speed to the starting motor.

Note:
Should a service replacement starter motor
be required the factory recommends replacement

with
original equipment parts; however, should the need arise an existing starter motor (Delco or
Prestolite) could be replaced with the current
Delco-Remy
starter, model 1108375, with the
following modifications to the wiring harness. If
the existing starter motor wiring harness
does
not
provide a 12 ga. purple conduit wire, (connects the ignition switch to the starter motor) then a 12 ga.

purple
conduit wire 70 inches long, must be in­

stalled.
Should the existing starter motor wiring
harness
contain a 16 ga. light blue conduit wire, (connects the ignition switch and starter motor)
bend this wire back and tape out of the way.

H-109.
Starting Motor Disassembly
a.
Before removing the starting motor from the
engine, disconnect leads and cover battery lead

terminal
with piece of
hose
or tape to prevent
short circuiting.
Note
locations of wiring connec­
tions to assure proper reconnection. Remove the cap screw that secures the starting motor to the
angle bracket on the side of the engine. Remove
the two cap screws that secure the drive end of
the starting motor to the cylinder block; remove
the starting motor.

b.
Remove terminal nut and disconnect field lead,

which
passes through grommet at top of motor,
from
motor terminal of solenoid. Remove two
thru

bolts
from motor. Remove commutator end frame

and
field frame assembly from solenoid and drive assembly.
e.
Pull
out pivot pins of brush holders and remove each of two brush holder and spring assemblies

from
field housing. Remove screws which attach
brushes and leads to holders.

d.
Remove armature and drive assembly from
drive
housing. Remove thrust collar from pinion
end of armature shaft. Remove leather thrust

washer
from
opposite
end of shaft.
e. To separate drive assembly from
armature,
place

a
metal cylinder of proper size (J^" [12,7 mm.]
pipe coupling is satisfactory) over end of armature
shaft to bear against the pinion
stop
retainer. Tap
retainer
toward armature to
expose
snap ring as
shown in
Fig.
H-47. Remove snap ring from
groove
in
shaft; slide retainer and pinion drive assembly

from
shaft. Remove assist spring from shaft,

f.
Remove two screws holding solenoid switch to
drive
housing remove switch. Remove small nut

and
insulating washer from the solenoid S terminal.
Remove nut and insulating washer from the
sole­

noid battery (large) terminal. Remove two screws that attach switch cover to solenoid and remove cover for inspection of switch parts. Remove shift
lever fulcrum bolt and remove shift lever, plunger,

and
return spring.
12765
FIG.
H-47—REMOVING PINION
DRIVE
ASSEMBLY

FROM
ARMATURE SHAFT

1— XA ' Pipe Coupling

2—
Snap
Ring
and Retainer

3—
Armature
Shaft
4—
Drive
Assembly
H-110.
Starting
Motor
Cleaning and
Inspection

a.
Wipe all parts clean with clean cloths. The
arma­
ture,
field coils, and drive assembly must not be
cleaned by any degreasing or high temperature
method.
This
might damage insulation so that a
short
circuit
or ground would subsequently develop.
It
would also remove lubricant originally packed

in
the overrunning clutch so that clutch would

soon
be ruined.

b.
Carefully
inspect all parts visually for wear or
damage. Make necessary repairs or replace unserv­
iceable parts. Any soldering must be
done
with

rosin
flux.

Note:
Never use acid flux when solding any elec­

trical
connections and never use emery cloth to
clean
armature
commutator or other
electrical
units. 208

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

H
H-111.
Brushes

Check
brush length. If brushes are worn to one-

half
their original length, replace them. Also check
for
cracks,
chips, damaged mounting holes, oil

saturation,
or other damage; replace brushes.

H-112.
Commutator

Check
the commutator for wear and discoloration.
If
the commutator is rough or worn the armature
should be removed and the commutator turned
down in a lathe. A discolored commutator should
be cleaned with carbon tetrachloride and inspected.

Scratches
on the commutator may be removed

with
sand paper. Use compressed air to remove

sand
particles after cleaning.

H-113.
Armature

Visually
inspect the armature for mechanical

defects
before checking for shorted or grounded
coils. Use a set of
test
probes for testing armature

circuits.
To
test
the armature for grounds, touch
one point of the
test
probes to a commutator
seg­
ment and touch the other point to the core or shaft.
Do not touch the points to the bearing surface or
to the brush surface as the arc formed
will
burn
the smooth finish. If the lamp lights, the coil con­
nected to the commutator
segment
is grounded.

H-114.
Field
Coils

Using
test
probes, check the field coils for both ground and open circuits. To
test
for ground, place
one probe on the motor frame or
pole
piece and
touch the other probe to the field coil terminals.
If
a ground is present, the lamp
will
light.

To
test
for open circuits, place the probes on the
field coil terminal and on an insulated
brush.
If
the light
does
not light, the coil is open circuited.

H-115.
Brush
Holder Inspection

Inspect
brush
holders for distortion, wear, and other
damage.
Check
that brush holders pivot freely on

their
pivot pins.
Check
brush spring tension with

a
spring scale. Hook the spring scale under the
brush
holder at the brush and
pull
on a line
paral­

lel
to the side of the
brush.
Note
scale reading just
as brush leaves commutator. Tension must be 35 oz. [9,925 kg.] minimum. Replace brush springs
if
tension is insufficient.

H-116.
Solenoid
Coils

Check
solenoid coil as follows:

a.
Remove screw from motor terminal of solenoid

and
bend field coil leads away from terminal.
Con­
nect terminal to ground with a heavy jumper wire.
See
Fig.
H-48.

b.
Connect a 12-volt battery, a high-current
vari­

able resistance, and an ammeter of 100 amperes

capacity
in series
between
S terminal of solenoid

and
ground; battery negative is to be connected
to ground. Connect a heavy jumper wire from
solenoid base to ground terminal of battery.
Con­

nect a voltmeter
between
base of solenoid and

small
S terminal of solenoid. Refer to Fig. H-48.
12455

FIG.
H-48—TEST CONNECTIONS,
STARTER
SOLENOID
COIL
1— S
Terminal

2—
Solenoid

3—
Ground
Connection 4—Voltmeter 5—Ammeter
6—
12-Volt
Battery
7—
Ground
Connection*
c.
Slowly decrease resistance until voltmeter
read­

ing increases to 10 volts.
Note
ammeter reading.

This
is current drawn by both windings in
parallel
;

it
should be 42 to 49 amperes at 10 volts, with solenoid at room temperature.

d.
Disconnect jumper wire from motor terminal
of solenoid. Increase resistance until voltmeter

reads
10 volts;
note
ammeter reading.
This
is
cur­

rent
drawn by hold-in winding only; it should be 10.5 to 12.5 amperes at 10 volts, with solenoid at
room temperature.
e. If solenoid windings do not rest within specifi­ cations given, replace solenoid switch assembly.

H-117.
Starting Motor Reassembly

a.
Lubricate
shift lever linkage and fasten in drive housing with lever stud.

Caution:
Do not lubricate solenoid plunger or solenoid cylinder.

b.
Install
return spring on solenoid plunger and

insert
plunger into solenoid cylinder. Apply sealing
compound on both sides of solenoid flange where it

extends
between
drive housing and field frame.

Attach
plunger to shift lever with fulcrum pin.

Fasten
solenoid to drive housing with two mount­
ing screws.

c.
Lubricate
armature shaft with silicone grease.
Install
assist spring and drive assembly on shaft

with
pinion outward.

d.
Install
pinion
stop
retainer on armature shaft

with
recessed side outward. Place a new snap ring on drive end of shaft and hold it in place with a
hard
wood block. Strike block with hammer to
force snap ring over end of shaft; slide the ring
down into
groove
in shaft. See Fig. H-49, left hand view. 209

H

ELECTRICAL
SYSTEM
FIG.
H-49—INSTALLING PINION
STOP RETAINER AND THRUST

COLLAR
ON ARMATURE SHAFT
1—
Retainer

2—
Snap
Ring

3—
Thrust
Collar

4—
Drive
Assembly 5—
Retainer

6—
Groove
in Armature Shaft 7—
Snap
Ring

e. Place thrust collar on armature shaft with shoulder next to snap
ring.
Move the retainer
into contact with
ring.
Using pliers on
opposite

sides of shaft,
squeeze
retainer and thrust collar

together
until snap ring is forced into the retainer.
See Fig. H-49, right hand view.

f.
Lubricate
bearing of drive housing with silicone grease and install armature and drive assembly
in
housing.
g. If field coils were removed from field frame, position coils of replacement field coil assembly
on
pole
shoes
and mount each
pole
shoe
in field
frame
with a
pole
shoe
screw. Use care in tighten­ ing screws to avoid distortion of parts. Be certain
that screws are securely tightened. Insert ends of
field
coil
leads through rubber bushing in field
frame.

h.
Position field frame assembly over armature as­
sembly so that its dowel pin
engages
the
hole
in

drive
housing. Use care to prevent damage to brushes and brush holders. Make sure that brushes

are
properly sealed on commutator.

i.
Install
leather thrust washer on commutator end
of armature assembly.
Lubricate
bearing in com­
mutator end frame with silicone grease and position
end frame to field frame so that armature shaft
enters bearing. Secure field frame and end frame
to drive housing with two
thru
bolts. Connect field leads to motor terminal of solenoid with connect­ing nut.

j.
Whenever the starting motor is disassembled
and
reassembled, the pinion clearance should be
checked.
This
is to make sure that proper clear­
ance exists
between
the pinion and the pinion

stop
retainer when pinion is in cranking position.

Lack
of clearance would prevent solenoid starter

switch
from closing properly; too much clearance
would cause improper pinion
engagement
in ring gear.

k.
Supply 6 volts (3 battery cells or a
6-volt
bat­

tery)
between
S terminal of the solenoid and ground (starter frame).
Caution:
Do not supply more than 6 volts or the
motor
will
operate. As a further precaution to
prevent motor operation, connect a heavy jumper

wire
from the solenoid motor terminal to ground.

I.
After energizing the solenoid, push the drive as­
sembly away from the
stop
retainer as far as pos­
sible and use a feeler
gauge
to check clearance

between
pinion and retainer. See Fig. H-50. If pinion clearance is not .010" to .140" [0,25 a 3,55

mm.],
there is either excessive wear or improper as­
sembly of solenoid linkage or shift lever mechanism.
12771
FIG.
H-50—MEASURING PINION CLEARANCE
1—
Press
Rearward

2—
Pinion

3—
Retainer

4— .010* to .140* Clearance 5—
Feeler
Gauge
210

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

H
Note:
Pinion clearance cannot be adjusted. If
clearance is not correct, motor must be disassem­
bled and checked for the above mentioned defects.

Any
defective parts must be replaced.
H-118. Starting Motor Test —
Genera!

To
obtain
full
performance data on a starting motor, or to determine the cause of abnormal
operation, the motor should be submitted to no-
load and locked armature
tests,
with equipment designed for such
tests.
A high-current variable resistance is required to obtain the specified volt­
age at the starting motor.
This
is necessary since
a
small variation in the
voltage
will
produce a
marked
difference in the current
drawn.

H-119.
Starting Motor No-Load Test

This
test
requires a DC voltmeter capable of
read­

ing
voltages
in a 12-volt
circuit,
a DC ammeter

with
maximum range of several hundred amperes,
a
high-current variable resistance, an rpm. in­

dicator,
and a fully-charged, 12-volt battery.

a.
Connect a jumper lead
between
S terminal
and
large battery terminal of starter solenoid.
Con­
nect voltmeter
between
either of
these
terminals (positive) and motor frame (negative, ground).

Connect
ammeter and variable resistance in series

between
positive terminal of battery and battery

terminal
of solenoid. Set up rpm. indicator to show starting motor speed.
b.
Initially,
adjust variable resistance to a value of
approximately .25 ohm. To complete the
circuit,

connect negative terminal of battery to motor

frame.
Adjust variable resistance to obtain a volt­ meter reading of 10.6 volts;
note
speed of starting motor and ammeter reading. Motor speed should
be
6750
to
10,500
rpm.; ammeter reading should
be 50 to 80 amperes.
c. Rated speed and current indicate normal condi­
tion of the starting motor. Low speed and high
cur­
rent
may show friction; this could be caused by
tight, dirty, or worn bearings, bent armature shaft,

or
a
loose
field
pole
shoe
dragging against the

armature.
It could also be caused by a short-cir­ cuited armature, or by grounded armature or field
coils.

d.
Failure
to operate and high current indicates

a
direct short circuit to ground at either the battery

terminal
or field coils.
e.
Failure
to operate and no current are usually
caused by broken brush springs, worn brushes, high insulation
between
commutator
bars,
or
some
other
condition preventing
good
contact
between
the brushes and commutator. It can also be caused by
open circuit in either the field coils or armature coils.
f. Low speed and low current show high resistance due to poor connections, defective leads, dirty com­
mutator, or one of the conditions mentioned in e,
above.
g. High speed and high current indicates a short
circuit
in the field coils. H-120-
Locked
Armature Test

This
test
requires a DC voltmeter with range ap­

propriate
to read
voltages
in a 12-volt
circuit,
a DC
ammeter with maximum range of several hundred
amperes, a high-current variable resistance, a
clamping fixture to lock
together
the motor shaft

and
case, and a fully-charged 12-volt battery.

a.
Connect a jumper lead
between
S terminal and
large battery terminal of starter solenoid. Connect
voltmeter
between
either of
these
terminals (posi­
tive) and motor frame (negative, ground). Connect
ammeter and variable resistance in series
between
positive terminal of battery and battery terminal
of solenoid.
Install
clamping fixture to lock motor
shaft and case
together
securely.
b.
Initially,
adjust variable resistance to approxi­
mately .05 ohm. To complete the
circuit,
connect
negative terminal of battery to motor frame. Ad­

just
variable resistance to obtain a voltmeter
read­
ing of 4.0 volts. Ammeter reading should be 280
to 320 amperes.

H-121.
Solenoid Starter Switch — Delco

The
solenoid-type switch is mounted directly on
the starting motor.
This
type of switch is energized
by turning the ignition key to the extreme right position. Should the solenoid switch
fail
in service

it
is necessary to install a new assembly.

Should
a starting motor
fail
to deliver maximum power the fault may be due to
voltage
drop at the

starter
switch contacts due to corrosion or burning.

Check
the switch by comparing the
voltage
at the
battery across the terminals. The
voltage
drop
should not exceed .05 volts per 100 amperes.
In
order to remove the starter solenoid, it is neces­

sary
to remove the starter assembly.

H-122.
ELECTRICAL
INSTRUMENTS

H-123.
Fuel
Gauge —
CJ-3B

The
fuel
gauge
circuit is composed of the indicating

unit,
mounted on the instrument panel, and the
fuel tank unit, connected by a single wire through the ignition switch.

Should
the
gauge
fail
to register, check all wire con­ nections to be sure they are tight and clean; also
be sure both units are well grounded. If, after this
check, the
gauge
does
not indicate properly, remove
the wire from the tank unit and connect it to a
new tank unit which must be grounded to the tank

or
frame for
test.
Turn
the ignition switch "ON"
and
move
the float arm through its range of travel,
watching the dash unit to determine if it indicates
correctly.
If it fails to do so the trouble is probably

in
the dash unit and it should be replaced.

Should
a new tank unit be unavailable for this
test,
disconnect tank unit wire at the instrument panel

gauge.
Connect one lead of a 12 V, 1 CP
test
light
to the instrument panel unit terminal and with the
ignition switch
"ON"
ground the other lead. If the
unit is operating correctly the pointer
will
move

approximately three-quarter across the
dial.
Do not attempt to repair either unit; replacement
is the only precedure. 211

H

ELECTRICAL
SYSTEM
H-124. Testing Indicators and Gauges

Two
gauges
(fuel and temperature) and two in­ dicators (oil pressure and battery charge) that are
located in the instrument cluster are electrically operated.

The
fuel
gauge
is connected by a single wire to a
float-and-slide-rheostat sending unit in the fuel
tank.

The
temperature
gauge
is connected by a single

wire
to a resistance-type sending unit mounted on the engine.

The
battery charge indicator operates when there
is a difference in potential
between
the generator
and
the battery
.The
battery charge indicator lights
when the generator is not charging the battery. The
indicator
light
goes
out when the generator
begins

to charge the battery.

The
oil pressure indicator is connected by a single

wire
to a diaphragm switch located on the engine.
When
engine
oil pressure is low or zero and the
ignition switch is on, the oil pressure indicator
will

light. When
engine
speed is increased slightly above idle speed, raising the oil pressure to approximately 6 psi. [0,2 kg-cm2], the diaphragm switch
will
open the circuit and the indicator light
will
go out.

A
voltage
regulator maintains a constant
voltage
to the
gauges
in normal operation. On early vehicles,
this
voltage
regulator was mounted on the
rear
of
the instrument cluster. On current vehicles, the
voltage
regulator is integral with the fuel
gauge.

Should
trouble
develop
in the
gauges,
first check the regulator (fuel
gauge
on current production vehicle). If the
voltage
to the regulator is below 10 volts system low
gauge
readings
will
result.
Voltage in
excess
of 16 volts
will
not affect
gauge

readings but may result in premature wear of the
regulator contacts. If the
voltage
to the regulator is

within
the above limits, check the electrical con­ nections to the regulator (or fuel gauge), especially
the ground connection. If the readings of all the
gauges
is too high, or they all read too low, replace
the regulator (or fuel gauge).

If
the temperature
gauge
or heat indicator in the
instrument cluster have failed, the cause may
originate from the jumper bar shorting out against the instrument case.
Check
the jumper bar
between

the temperature
gauge
and heat indicator at the

rear
of the instrument case. On later production vehicles, the jumper bar is covered with an in­
sulating
sleeve
to protect it from shorting out
against the instrument case. If the jumper bar

does
not have this
sleeve,
either install one or

wrap
the bar with plastic electrical tape to
half

an
inch [12,7 mm.] from each end. When installing the jumper bar, be sure the curved
segment
is
closest to the fuel
gauge.

Should
only one of the two
gauges
register incor­
rectly,
check the lead wire from the
gauge
to the
sending unit for shorts or open connections. Next disconnect the
gauge
from the sending unit, and
connect the
gauge
to a new fuel tank sending unit

which
has been grounded to the vehicle.
If
the
gauge
registers incorrectly when operating the new unit,
replace the
gauge;
if correctly, replace the sending

unit.

Should
a new fuel tank unit not be available for testing, use a 12-volt
test
light in its place. When
the
gauge
is operating correctly, the pointer
will

move
approximately three-quarters across the
dial.

On
some
vehicles, the temperature
gauge
may
register on or
close
to the H (hot)
mark
when
coolant temperature is
190°F.
to
200°F.
[88°C.
a

93°C.].
In such cases, a 25-ohm,
1-watt
resistor
may be installed on the temperature
gauge
which

will
place the pointer just beyond the center
mark
at a coolant temperature of
190°F.
to
200°F.
Install

the resistor
between
the two terminals on the back
of the
gauge.
Insulate the
exposed
leads of the resistor with electrical tape.

If
the oil pressure indicator
does
not indicate cor­

rectly,
first check the light bulb. Next check all
connections and lead wires. If, after all possible

defects
are corrected, the indicator light
does
not go on and off properly, then the diaphragm type
switch in the cylinder block should be replaced.

H-12S.
LIGHTING SYSTEM The
wiring of the lighting systems is shown in
the wiring diagrams, which indicate the various units in relation to their positions in the vehicle.
The
wires in the various circuits are of different
colors or are marked by tracers to aid when check­
ing individual circuits.

The
lighting circuits of all models are protected by

an
overload circuit breaker mounted on the back of the main light switch and no replaceable fuse is
required.

The
upper and lower headlight beams are con­
trolled by a
foot
switch located on the toe board
to the left of the clutch pedal.
H-126.
Main
Light
Switch

This
switch is a dual functioning unit having two

push-pull
positions and a rotary action. When
pulled out to the first position, the front parking
and
tail
lights are turned on. When pulled all the
way out to the second position, the headlights and
tail
lights are turned on. Rotating the switch to
the right dims the instrument cluster lighting.

The
switch may be removed from the instrument
panel by first loosening the set screw in the control
knob and removing the knob. The retaining nut may then be removed and the switch removed
through the
rear
of the instrument panel.
FIG.
H-51—MAIN
LIGHT
SWITCH
(EARLY)

1—
Battery
4—Parking Lights
2—
Rear
Lights 5—Auxiliary

3—
Head
Lights
212