1953 JEEP DJ bulb

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

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL
H

FIG.
H-52—MAIN
LIGHT SWITCH (LATE)
1—
Circuit
Breaker

2—
Light
Switch

3—
Rear
Lights

4—
Head
Lights
5—
Parking
Lights
The
light switch shown in
Fig.
H-51 was superseded
by the one shown in
Fig.
H-52.

H-127.
Headlight Dimmer Switch To
remove the headlight dimmer switch, first raise
the hood and disconnect the wires attached to the

switch.
Then
remove the two screws that hold the

dimmer
switch to the floor board. Remove the

switch.
Check
the operation of the dimmer switch

with
a
test
light. A
circuit
across two different pairs of contacts (one to headlights, the other to the
high-beam indicator light) should alternately light
the
test
lamp when the switch is operated.
H-128.
Stop Light Switch
The
stop
light switch is of the diaphragm type.

Should
the switch
become
inoperative, it is neces­

sary
to install a new one.
Current
production vehicles are equipped with two
stop
light switches
that operate independently of each other. Both
switches are located along the
left
side of frame, in the front and
rear
brake lines.

Caution:
Do not apply the brakes while making
this exchange as air may enter the hydraulic line.
Bleed
the brakes after replacing the switch.

Fig.
H-54 shows the wiring of the
stop
light
circuit.
11500

FIG.
H-53—STOP
LIGHT SWITCH
FIG.
H-54—STOP
LIGHT CIRCUIT

1— Stop
Light
Switch
2—
Light
Switch

3—
Tail
Light
H-129. Head Lamp Service

H-130.
Head Lamp Replacement

Refer
to Fig. H-59.

Each
sealed beam head lamp can only be replaced as a
complete
unit.

A
sealed beam unit may be replaced by the fol­ lowing procedure:

a.
Remove door screw.

b.
Remove door.

c.
Remove retaining screws and retaining
ring.

d.
Remove sealed beam unit.
Installation
of sealed beam unit is the reverse of
above procedure. When replacing head lamps,

check
lamp aim following procedures described in

Par.
H-132.

FIG.
H-55—PARKING
LIGHT (EARLY)

1—
Bezel

2—
Lens

3—
Bulb

4—
Gasket
5—
Housing
and Cable

6—
Screw
213

H

ELECTRICAL
SYSTEM

14379

FIG.
H-56—PARKING
AND SIGNAL LIGHT (LATE) 1—
Screw

2—
Lens
3—
Gasket

4—
Bulb
5—
Cable

6— Housing H-131. Head
Lamp
Aiming Preparation

All
Jeep Universal-series lamps must be aimed on
the low beam. Lamps may be aimed either with mechanical aimers or by using a screen. If me­

chanical
aimers C-3674 are used,
follow
instruction
supplied with the aiming equipment. If a screen is to be used, preparation for aiming is as follows:

a.
Locate the vehicle in a darkened area with a level floor area and with a screen (may be a wall) having a nonreflecting white surface. A reference
line should be marked on the floor 25
feet
[7,62 m.]
away from and parallel to the screen. Position the vehicle perpendicular to the screen and with the
front head lamps directly over the reference line.
b. Locate the middle
tape
on the screen so that
it is aligned with the center line of the vehicle.
c. Equalize all tire pressures.

d.
Rock the vehicle from side to side to equalize springs and shock absorbers.
e. Measure the distance
between
vehicle head lamp centers.
Then,
position marker
tapes
vertically on
the screen to the right and
left
of the middle
tape
at half this distance.

f.
Measure the distance from the center of each
lamp to the surface on which the vehicle rests.
Position a marker
tape
horizontally on the screen

FIG.
H-57—TAIL, STOP AND

DIRECTIONAL
LIGHT
1—
Screw

2—
Lens

3—
Gasket

4—
Bulb
5— Housing and Cable Assembly
6— Nut and Lockwasher 10441
FIG.
H-58—TAIL AND
STOP LIGHT (EARLY)

1
—Ring

2—
Lens
3—
Gasket

4—
Retainer
5—
Bulb
6—
Gasket

7— Housing and Socket 214

ELECTRICAL
SYSTEM

14385

FIG.
H-61—BACK-UP
LIGHT
1—
Snap
Ring
2—
Lens

3—
Gasket

4—
Bulb
5—
Housing
and
Cable
On
late production
T14A
transmissions the backup
light switch is threaded into the right
rear
corner
of the cover housing and is activated by the move­
ment of the reverse shift
rail.

The
backup light switch is not serviceable and
must be replaced if defective.

Bulbs
can be replaced by removing the snap
ring,

lens and gasket from the assembly.

H-136.
License Plate
Light

On
CJ-5A,
CJ-6A
and current production vehicles
the license plate light is attached to the tailgate
and
is of the swing-type design to enable the
license plate to be visible when the tailgate is in
the down psoition. The bulb can be changed by
removing
the clear plastic lens. On early production
vehicles the license plate light is integral with the

tail
light assembly.

H-137.
Horn
The
horn is mounted under the hood on the
left

front
fender. The horn is sounded by pressing the
button located at the top center of the steering
wheel.

To
remove the horn wire, disconnect the wire at
the snap connection at the base of the steering
column.
Pull
off the rubber horn button cap and
the brass contact cap from the steering wheel nut.

This
will
expose
the contact tip of the horn wire.

Pull
the wire out of the steering column from the top. Refer to Fig. H-62.

H-13S.
Directional
Signals

Fig.
H-63 shows the
wiring
of a
composite
direction­

al
signal
circuit.
The most frequent causes of
failure
in
the directional signal system are
loose
connec­
tions and burned-out bulbs. A flashing rate

approximately
twice the normal rate usually in­
dicates a burned-out bulb in the
circuit.
11087

FIG.
H-62—HORN
BUTTON 1—
Cap
2— Nut
3—
Horn
Button
Spring
Cup 4—
Ferrule

5—
Horn
Cable

6—
Contact
Disc

7—
Steering
Wheel
8—
Cup
9—
Bearing
Spring
Seat
10—
Steering
Column

11—
Tube

12—
Bearing

13—
Bearing
Spring

14—
Horn
Button
Spring

15—
Retainer
Spring
When
trouble in the signal switch is suspected it
is advisable to make the following
test
to definitely
locate the trouble before
going
to the effort of

removing
the signal switch. If, for example, the
right
rear
stop
light and right front parking light

are
inoperative and switch failure is indicated, first put the control lever in neutral position.
Then

disconnect the wire to the right side
circuit
and
touch it to or bridge it to the
"L"
terminal, thus
by-passing the signal switch. If the right side cir- 10609

FIG.
H-63—DIRECTIONAL SIGNAL
CIRCUIT

1—
Flasher

2—
Ignition
Switch

3—
Control
4—
Light
Switch
5— Stop
Light
Switch
216

H

ELECTRICAL
SYSTEM
H-152.
ELECTRICAL
SPECIFICATIONS—Continued

HURRICANE DAUNTLESS
V-6
DAUNTLESS
V-6 ENGINE
MODEL -
F4
ENGINE
ENGINE
LATE
MODELS

EARLY
MODELS
IGNITION
COIL
BALLAST
]Make Delco-Remy
Prestolite Prestolite
Model
None

1957154

PU
5003

PU
5003

Ohms • • 1.80 @
80°F.

.495 - .605 @
75°F.

.495 - .605 @
75°F.

1.80 @
80°F.

.638 - .835 @
212°F.
.638 - .835 @
212°F.

DISTRIBUTOR:
Prestolite Delco-Remy Prestolite Prestolite
Model
•
(a)
LAY
4012, 4401

1110376

I
AT
4501 or
IAT
4502A
(b)
I
AY
4401A, 44011

IAT
4502

Breaker
Point Gap (b)
.020"
[0,508
mm.] .016"
[0,406
mm.] .016"
[0,406
mm.]
.016"
[0,406
mm.]

Breaker
Arm Tension. ..... 17 to 20 oz.
19 to 23 oz. 17 to 22 oz. 17 to 22 oz.
[482 a 567 gr.] [538 a 652 gr.] [482 a 624 gr.]
[482 a 624 gr.]

42° 29°
to 31°
29°
±3°
29°
±3°

Max.
Auto Advance
(Crankshaft
Degrees) •(a)
11°
@ 1,700 rpm.

13°
to
15°
at 1,950 rpm.
16°
@ 1,800 rpm.
21°
(2 1,800 rpm.

(Crankshaft
Degrees)
(b)
13.5°
@ 1,700 rpm.

26°
@
4200
rpm.
32°
@
4200
rpm.

Max.
Vac. Advance go
(Distributor Degrees)., . .
None

8° 8°
go
Condenser Capacity. . .25 to .28 mfd. .18 to .23 mfd. .25 to .28 mfd. .25 to .28 mfd.

TIMING:
Crankshaft
See
Note

See
Note
See
Note
See
Note

Mark
Location............
Crankshaft
Pulley

Crankshaft
Pulley

Crankshaft
Pulley

Csankshaft
Pulley

Firing
Order
1-3-4-2

1-6-5-4-3-2
1-6-5-4-3-2 1-6-5-4-3-2

SPARK PLUGS:
Make
Champion

A.C. A.C.
or Champion
A.C.
or Champion

J8
44S
44S or UJ 12Y 44S or UJ 12Y

Thread
14 mm.
14 mm. 14 mm. 14 mm.

Thread
Reach
Vz"
[9,47 mm.]
%"
[9,47 mm.]

¥%"
[9,47 mm.]
V8" [9,47 mm.]

Gap
.030"
[0,762
mm.]
.035"
[0,900
mm.] .035"
[0,900
mm.] .035"
[0,900
mm.|

LAMP BULB TRADE
NUMBERS:

Headlight 6012
6012 6012 6012

Parking
and Directional Signals. 1157NA
1157NA 1157NA 1157NA

License
Plate Light........ 1155
1155 1155 1155

Marker
and Reflector 194
194 194 194

INDICATOR LIGHTS:
57 57 57 57
Directional Signals........ 57
57 57 57

Charge
57
57 57 57
57 57 57 57
1156 1156 1156 1156
Instrument Cluster 57 57 57 57

Warning
— 4 Way Flasher. . 57
57 57 57

Brake
Warning Light 57
57 57 57

FUSE
DATA:
Heater 9 amp. 9 amp. 9 amp. 9 amp.

Backup
14 amp. 14 amp. 14 amp. 14 amp.

WS/Wiper.
14 amp. 14 amp. 14 amp. 14 amp.
Directional Signal 9 amp. 9 amp. 9 amp. 9 amp.
4-Way Flasher 14 amp. 14 amp. 14 amp. 14 amp.

Brake
Warning Light 9 amp. 9 amp. 9 map. 9 amp.

FLASHER
DATA:
Directional Signals. 144
144 144 144

Hazzard
Warning. 170
170 170 170

NOTE:
0°
T.D.C.
on Distributor
models
IAY 4401A, IAY 4401B, IAT 4502A.

NOTE:
5°
B.T.C.
on Distributor
models
IAY 4012, IAY 4401, IAT 4501, IAT 4502,
1110376.
224