service JEEP CJ 1953 Service Manual

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

H
11514

FIG.
H-2—WIRING
DIAGRAM—MODEL
CJ-3B
(Serial No.
35522
and
after)

1—
Left
Headlamp
2—
Left
Parking and Signal Lamp
3— Right Parking and Signal Lamp
4— Right Headlamp 5— Battery Ground Strap
6— Generator 7— Ignition
Coil

8— Junction Block
9—
Horn

10— Distributor
11— Battery
12—
Voltage
Regulator 13— Starting Motor
14—
Oil
Pressure Signal Switch 15— Temperature Sending Unit
16—
Solenoid
Switch 17— Foot Dimmer Switch
18—
Stop
Light Switch 19— Directional Signal Flasher
20— Fuse
21—
Light
Switch 22— Directional Signal Switch
23—
Horn
Button 24— Ignition and Starter Switch 25—Instrument Cluster
A—Upper Beam Indicator
B—Turn
Signal Indicator C—Instrument Lights

D—Oil
Pressure Indicator
E—Charging
Indicator F—Temperature Gauge

G—Fuel
Gauge
H—Instrument
Voltage
Regulator
25—Fuel Gauge Tank Unit
27—
Left
Tail
and
Stop
Lamp
28— Right
Tail
and
Stop
Lamp 175

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

H

12968
FIG.
H-4—WIRING
DIAGRAM—MODELS
CJ-5, CJ-6, DJ-5, DJ-6
LATE
F4
ENGINE

1—
Left
Headlamp
2—
Left
Parking and Signal Lamp
3— Right Parking and Signal Lamp 4— Right Headlamp
5— Generator
6— Ignition Distributor
7—
Oil
Pressure Sending Unit
8— Junction Block
9—
Horn

10— Foot Dimmer Switch 11—
Stop
Light Switch — Front
12— Temperature Sending Unit
13— Ignition
Coil

14— Starting Motor 15— Battery Ground Cable
16— Battery
17— Voltage Regulator 18—
Fuse

19— Instrument Cluster

A—Hi-Beam
Indicator

B—Auxiliary
C—Instrument
Lights

D—Oil
Pressure Indicator
E—Charging
Indicator
F—Temperature
Indicator

G—Fuel
Gauge
H—Instrument Voltage Regulator
20— Ignition and Starter Switch 21—
Flashei
(Directional Signal)
22—
Horn
Button 23— Directional Signal Switch
24— 4-Way Flasher Switch
25—
Flasher
(4-Way)
26—
Fuse

27—
Main
Light Switch 28—
Stop
Light Switch — Rear
29—
Fuel
Gauge
Tank
Unit
30—
Back-Up
Light Switch
31— Right
Tail
and
Stop
Lamp
32— Right Back-Up Lamp
33—
Left
Back-Up Lamp
34—
Left
Tail
and
Stop
Lamp

in
which the key can be removed. Turning the key
to the
left
energizes
auxiliary
equipment
such as
windshield wipers, radio, and heater. The turn
signal
lights
will
operate
with the
ignition
key in
either the
left
or right
position.
The
ignition
switch is held in
position
by a
tension
spring on the back
of the instrument panel and a
notched
bezel on
the front of the instrument panel.
H-8.
Lighting System

The
wiring for the lighting
system
is shown in the
wiring diagrams, Figs. H-2 thru H-7 of the manual,
which indicate the various units in relation to their

position
in the vehicle. The lighting circuit is pro­
tected
by an overload circuit breaker
mounted
on the rear of the light switch.
The
main light switch controls the lighting
system
177

H

ELECTRICAL
SYSTEM

14365

FIG.
H-5—WIRING
DIAGRAM—F4
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—
Generator
7—
Distributor

8—
Ignition
Coil

9— Starting Motor
10— Battery Ground Cable
11—
12
Volt
Battery

12—
Flasher
(Directional Signal)
13— 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
14—
Ignition
and
Starter
Switch
15—
Horn
Button 16—
Directional
Signal Switch 17— 4-Way
Flasher
Switch
18—
Flasher
(4-Way)
19—
Windshield
Wiper Motor Switch
20—
Main
Light
Switch

21—
Fuel
Gauge
Tank
Unit

22—
Back-Up
Light
Switch
23—
Marker
Lamp — Red 24—
Right
Tail
and Stop Lamp
25—
Right
Back-Up Lamp
26—
Left
Back-Up Lamp
27—
Right
Tail
and Stop Lamp
28—
Marker
Lamp — Red 29— Stop
Light
Switch
30— Foot Dimmer Switch

31—
Windshield
Wiper Motor Assembly

32—
Voltage Regulator
33— Temperature Sending
Unit

34—
Oil
Pressure
Sending
Unit

35— Spark
Plugs
&
Cables

36—
Horn

37— Junction Block
38—
Marker
Lamp — Amber
through a
two-position
push-pull switch located on
the
left
side
of the control panel.
The
foot-operated
headlight dimmer switch is
mounted on the floorboard to the
left
of the steering
column.

H-9.
PRESTOLITE
DISTRIBUTOR
—
DAUNTLESS
V-6 and

HURRICANE
F4
ENGINE

The
Prestolite distributor on the F4
engine
is
mounted on the right
side
of the
engine
and is op­
erated by a coupling on the oil pump shaft, see Fig.
D-l,
which is driven by a spiral gear on the cam­
shaft. The spark advance is fully automatic, being controlled by built-in centrifugal
weights.
The Pres­

tolite
distributor on the V-6
engine
(Fig. H-8) is mounted at the
left
front of the
engine
on the tim­
ing chain cover. It is driven by a spiral gear on the
camshaft. The spark advance is fully automatic,
being controlled by built-in centrifugal
weights,
and by a vacuum advance system. While
some
parts of the distributor may be checked or replaced
with the unit mounted on the
engine,
it is
best
to periodically remove it for a thorough check. Infor­ mation covering the parts which can be serviced
without removal is
given
below.
The
Prestolite distributor installed on the V-6 en­

gine
is similar in construction to the distributor in­
stalled on the F4
engines
except
for the addition of

a
vacuum advance mechanism.
The
same checking procedures outlined in Par. C- 10a, are used for the Prestolite V-6 distributor with

exception
of specifications.
H-10. Distributor Cap

The
distributor cap should be inspected for cracks,
carbon runners and
evidence
of arcing. If any of

these
conditions
exists, the cap should be replaced.
Clean
any corroded high
tension
terminals.

H-11.
Rotor
Inspect the rotor for cracks or
evidence
of
excessive

burning at the end of the metal strip.
After a distributor rotor has had normal use the
end of the rotor will
become
burned. If burning is found on top of the rotor it indicates the rotor is
too short and
needs
replacing. Usually when this condition is found the distributor cap
segment
will 178

'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

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

H

12955

FIG.
H-8—PRESTOLITE
DISTRIBUTOR—DAUNTLESS V-6 ENGINE 1—
Cap
2—
Rotor

3—
Lubricating
Wick

4—
Snap
Ring
5—
Condenser

6—
Contact
Set 7—
Breaker
Plate
8—
Cam
and Stop Plate 9—
Spring
(2)
10—
Governor
Weight

11— Cam
Spacer

12—
Gear
13—
Gear
Pin
14—
Washer

15—
O-Ring
Seal
16—
Bushing

17—
Distributor
Housing 18—
Vacuum
Chamber
19—
Washer
(Nylon)
20—
—Cap
Clamp
and Rings

21—
—Primary
Lead
22—
Washer
(outer upper,

23—
Washer
(inner upper)

2".—Drive
Shaft
H-14. Governor Mechanism
The
centrifugal advance mechanism consists of

an
automatic cam actuated by two spring con­
trolled centrifugal weights. As the
speed
of the distributor shaft increases with
engine
speed, the

weights
are thrown outward against the pull of the springs.
This
advances the cam causing the contact
points
to
open
earlier and thus advancing the

spark.
The centrifugal
type
governor should be checked for free operation. Hold the governor shaft
and
turn the cam to the
left
as far as possible

and
release it. The cam should immediately return to the original position without drag. Should a distributor
test
fixture be available it is

best
to make a check through the entire advance
range, following the instructions of the fixture manufacturer.

The
vacuum control unit is mounted separately
on the
outside
of the distributor housing on the
V6
Prestolite distributor.
The
vacuum control unit consists of an enclosed
spring-loaded diaphragm linked mechanically to the distributor. The air-tight side of the diaphragm
is connected to the intake manifold side of the

carburetor.
Under part throttle operation, the in­take manifold vacuum is sufficient to actuate the
diaphragm and cause the distributor to rotate in
its mount, thus advancing the spark and increasing fuel
economy.
During acceleration or when the
engine
is pulling heavily, the vacuum is not suf­
ficient to actuate the diaphragm and the distributor
is held in the retarded position by a calibrated

return
spring which bears against the vacuum
diaphragm.

H-15.
Distributor Removal

a.
Remove high-tension wires from the distributor cap terminal towers, noting the order in which
they

are
assembled to ensure correct reassembly.
b. Remove the primary lead from the terminal

post
at the coil.
c. Unlatch the two distributor cap springs and re­
move
the cap.

d.
Note
the position of the rotor in relation to the
base.
This
should be remembered to facilitate re­ installing and timing.
e. Remove the screw holding the distributor to the

crankcase
and lift the assembly from the
engine.

H-16.
Prestolite Distributor Disassembly

Refer
to Fig. H-8 and H-9.

a.
Remove the rotor. b. Remove the condenser.
c. Remove the distributor points.
d.
Remove nylon washer attaching vacuum ad­vance arm to breaker plate, V6 only. Remove two 181

H

ELECTRICAL
SYSTEM
FIG.
H-9—DISTRIBUTOR ASSEMBLY- HURRICANE F4 ENGINE 1—
Cap
6—Advance Plate
Lock
Screw
2—
Rotor
7—Oiler and
Felt
Wick

3—
Primary
Wire
8—Drive Shaft
4—
Breaker
Plate 9—Drive Shaft
Collar
and
Thrust
Washer 5—
Governor
Weights
attaching screws; remove vacuum advance unit
from housing.
e. Remove the two clamp
hinge
to breaker plate
screws; remove breaker plate from housing.
f. Remove the shaft assembly. To do this, file off
the upset end of the pin which is placed through
the collar and shaft at the lower end of the housing

and
drive out the pin with a suitable punch. Re­
move
the collar and washer.
Pull
the shaft from
the housing.
g. Should it be necessary to remove the cam as­
sembly, first remove the
felt
wick from the upper
end. Use
long-nose
pliers to compress and remove the spring locking clip located at the
bottom
of the

drilled
center opening of the cam. Remove the cam.

H-17.
Distributor Inspection

If
the shaft and bearings are worn sufficiently
to allow .005" or more
looseness
of the shaft,
they
must be replaced. Before installing new bearings,
soak them in medium grade
engine
oil and allow
them to
drain.
Wipe all oil from the upper part of
the housing.

Important:
After new bearing installation,
drill
a

y%"
[3,2 mm.] lubrication
hole
through the upper bearing
before
installing the drive shaft. Refer
to Fig. H-8 item 16.

At
assembly, apply a film of grease to the upper
drive
shaft washer and put a small amount of
grease in the bearing bore just
above
the bearings.

Lubricate
the governor mechanism sparingly with
medium grade
engine
oil in the oiler mounted on
the side of the housing and 5 drops on the
left

located in the center opening of the cam directly

below
the rotor. Place a very light smear of grease
on the cam and 1 drop of oil on the breaker arm pivot.
Before installing the distributor, check the friction

spring
mounted on the lower end of the drive shaft

and
replace it if worn or damaged. Inspect rod end of vacuum advance mechanism
for
excessive
wear. Push rod
into
unit as far as
possible, hold finger tightly over nipple, then release rod. After about 15 seconds, remove finger
from nipple, and
notice
if air is drawn
into
unit.
If
not, diaphragm is leaking and unit must be
replaced.

H-18.
Installation and Ignition
Timing

If
the
engine
crankshaft has
been
rotated, with the
distributor off, it
will
be necessary to place No. 1
piston in firing position to correctly install the distributor. Refer to
Pars.
C-10 and
C-ll. Oil
the distributor housing where it bears in the

cylinder
block and install the distributor on the
cylinder
block. Mount the rotor on distributor shaft

and
turn
the shaft until the rotor
points
towards No. 1
spark
terminal tower position (when cap is installed) with the contact
points
just breaking. Move the rotor back and forth slightly until the

driving
lug on the end of the shaft enters the
slot

cut in the oil pump gear and slide the distributor
assembly down
into
place. Rotate the distributor
body
until the contact
points
are just breaking.
Install
the hold down screw.

H-19.
Ignition
Coil
— F4 Engine

The
sealed coil
does
not require any special service
other than keeping the terminals and wire con­ nection clean and tight.

The
positive (+) terminal of the coil is connected
to the ignition switch and is also connected directly
to the starter solenoid to by-pass the resistance

during
cranking of
engine.

The
negative
(—) terminal is connected to the
distributor. The secondary (High tension) terminal
is connected by a short cable to the center terminal

in
the distributor cap.

Note:
Always make certain the coil wires are con­
nected to the proper coil terminals to ensure cor­
rect coil polarity.

H-20. DELCO DISTRIBUTOR
—
DAUNTLESS
V-6
ENGINE
The
distributor (Fig. H-10) is mounted at the
left

front of the
engine
on the timing chain cover. It
is driven by a
spiral
gear on the camshaft. The

spark
advance is fully automatic, being controlled 182

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL

H
|
13399

FIG.
H-10—DELCO
DISTRIBUTOR—
DAUNTLESS
V-6
ENGINE

1—
Rotor
8—Vacuum
Unit

2—
Window
9—Breaker Cam
3—
All
Weather Cap
10—Drive
Gear

4—
Cap
Latch
11—Primary Lead 5—
Rotor
Mounting
Screw 12—Contact Set
6—
Lock
Washer 13—Condenser

7—
Advance
Mechanism
by
built-in
centrifugal weights, and by a vacuum

advance
system. Contact point opening is adjusted
through
a window in the distributor cap
while
the engine is
idling.
Some
parts
of the distributor may be checked or replaced
with
the distributor mount­
ed on the engine, but it is
best
to remove it periodi­
cally
for a thorough check. Information on
parts

which
can be serviced without removal is given
below.

Note:
Prestolite and Delco distributors are inter­

changeable
on V-6 engine equipped vehicles.

H-21.
Distributor Cap
The distributor cap should be inspected for cracks,
carbon runners and evidence of arcing. If any of

these
conditions exist, the cap should be replaced. Clean any corroded high tension terminals.

H-22.
Rotor
Inspect the rotor for cracks or evidence of
exces­

sive burning at the end of the metal strip.
After
a distributor rotor has had normal use, the
end of the rotor
will
become
burned. If burning is
found
on top of the rotor it indicates the rotor is too short and
needs
replacing. Usually when this
condition
is found the distributor cap
segment
will

be burned on the horizontal face and the cap
will

also
need
replacing.
H-23.
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
ccnaenser
be leaky a weak spark
will
result. Check the
condenser
lead for broken wires or

frayed
insulation.
Clean and tighten the connections
on
the terminal
posts.
Be
sure
the
condenser
is mounted
firmly
on the distributor for a good ground
connection.

Should
a
condenser
tester
be available the capacity
should check
from
.18 to .23 microfarads. In the

absence
of a
tester
check by substituting new con­
denser.

H-24. Distributor Points

a-
Examine distributor points. Using
Tool
C-4094, check point contact spring
pressure,
should be 19 to 23 oz. [0,538 a 0,652 kg.]. Install new points

if
they are
worn,
pitted,
mate
poorly, or show
signs

of
metal transfer. Should premature
ignition
point

failure
occur
because
of dust entering the
distri­

butor cap and causing
excessive
wear to the
ignition

point
fiber block, perform the
following
correc­
tions after installing new distributor points.
FIG. H-l
1—SEALING
DISTRIBUTOR
CAP

1—Caulking
Compound
183

H

ELECTRICAL
SYSTEM

14237

FIG.
H-l2—DRILLING DISTRIBUTOR
CAP 1—%'
Vent
Hole
Location
Seal
the distributor cap access window and the

area
beneath the distributor cap with caulking
compound as shown in
Fig. H-ll.
At approximately
180°
from the distributor cap access window,
drill
a
[2,38 mm.] vent
hole
[31,75
mm.]
from the
bottom
of the distributor cap as shown

in
Fig. H-l2. b. To adjust breaker point cam dwell, refer to

Par.
C-10.

H-25.
Centrifugal Advance

Refer
to Fig. H-13.
Inspect for
excessive
wear
between
centrifugal

weights
and advance cam, or pivot pins.
Turn

weight
base plate in a clockwise direction until

weights
are fully extended, then release and allow springs to return to retard position. Repeat several times. Springs should return
weights
to
stop
with­out sticking and there should be no
excess
free

movement
in the retard position.

H-26.
Distributor Removal

a.
Disconnect the distributor primary wire from
coil
and disconnect
hose
from vacuum advance
mechanism of distributor. Insert a screwdriver in upper
slotted
end of two distributor cap retainers.

Press
downward, and turn 90
degrees
counterclock­
wise to release. Remove cap from distributor hous­ ing.
b. Make an index
mark
on distributor housing

(Fig.
H-14) in line with center of rotor. Carefully

note
the direction the vacuum unit
points
in
rela­

tion to
engine
so that the distributor can be in­
stalled in the same position after it is serviced.

Caution:
If
engine
is turned over while distributor is removed,
complete
ignition timing procedure
must be followed upon distributor installation.
c. Remove attaching cap screw and distributor
clamp from timing chain cover.
Lift
distributor up­

ward
and remove it from timing chain cover.

H-27.
Distributor Disassembly (Delco)

Refer
to Fig. H-l5.

a.
Remove rotor, breaker point assembly, and capacitor from distributor.
FIG.
H-13—CENTRIFUGAL ADVANCE
MECHANISM (DELCO)
A—No
Advance
1—
Advance
Weights

2—
Advance
Cam
B—Full
Advance

3—Full
Advance
FIG.
H-14—DELCO DISTRIBUTOR

ROTOR
POSITION
1
—Rotor
Tip
Lined
Up
With
Notch

184

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL

H
FIG.
H-l 5 -DELCO
DISTRIBUTOR—
DAUNTLESS V-6 ENGINE

1—
Cap Assembly
2— Rotor
3— Governor Weight
4— Rotor
Mounting
Screw 5—
Lock
Washer
6—
Weight
Spring (Governor) 7— Shaft
8— Cam Assembly
9—
Gear
Pin
10—
Drive
Gear

11—
Spacer
Washer
12—
Housing

13—
Vacuum
Control
14—
Lock
Washer

15—
Control
Mounting
Screw
16—
Primary
Lead
17— Lead Gromet
18— Washer

19—
Breaker
Plate

20—
Condenser

21—
Retaining
Spring
22—
Ground
Lead
23—
Condenser
Clsmp
24— Contact Set
25— Clamp Screw

26—
Lock
Washer
27— Contact Screw

28—
Insulator 29—
Spring
Clip

30—
Screw 13400

b.
Remove and discard
O-ring
seal from distributor
housing.
c. Remove two attaching screws; remove vacuum
advance from housing.

d.
Drive pin from driven gear and shaft, using a
y%"
[3,2 mm.] straight punch. See Fig. H-l6.

Caution:
Be careful not to bend distributor shaft
or damage gear when driving pin out.

e.
Remove gear and thrust washer from shaft; pull the shaft, breaker cam, and centrifugal advance
mechanism from the housing.
f. Remove two springs and centrifugal advance
weights
from the integral
weight
base plate and

breaker
cam. Remove plate from end of shaft.
g. Remove retainer breaker plate, and
felt
washer from upper bushing.

Note:
Lubricant
reservoir contains sufficient
lubri­

cant for the life of the distributor. Do not
move
plastic reservoir cover from housing. Do not de-
grease bore of housing.
h. Remove distributor primary lead and grommet
from housing.

Caution:
Do not attempt to replace the shaft
bushings in the housing; the housing and bushings

are
serviced only as an assembly.
FIG.
H-l6—DISTRIBUTOR GEAR AND
SHAFT PIN REMOVAL (DELCO) 1— H' Punch

2—Spring
Pin
H-28.
Distributor Parts
Cleaning
and

Inspection

a.
Wash the distributor housing, shaft, gear, break­

er
plate, and
weight
base and cam in suitable clean­ ing solvent. Hold housing in horizontal position to
avoid
getting
cleaning solvent
into
the lubricant
reservoir.
Dry parts thoroughly.

b.
Wipe distributor cap with a clean cloth. Inspect
it for chips,
cracks,
and carbonized paths which
would allow
high-voltage
leakage. Such
defects
re­
quire
replacement of cap.
Clean
loose
corrosion
from surfaces of terminal
segments
inside the cap. Do not use emery cloth or sandpaper. If
segments

are
deeply
grooved, the cap should be replaced.

Pull
cables from terminal
sockets
and inspect
sockets
for corrosion.
Clean
sockets, using a stiff

wire
brush to
loosen
corrosion.

c.
Inspect rotor for wear and damage. If rotor is
cracked,
spring contact is badly worn, or rotor tip is badly burned, rotor must be replaced. 185

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

H

12746

FIG.
H-l8—VACUUM
ADVANCE
MECHANISM
(DELCO)

A—Full
Advance

B—No
Advance
1—Vacuum
Pull
Rod
e.
To adjust breaker point cam dwell and set tim­
ing of engine, refer to
Pars.
C-10 and
C-ll.
H-31. Coil
— V-6 Engine

The
sealed coil
does
not require any special service
other than keeping the terminals and wire connec­
tions clean and tight.

The
positive (+) terminal of the coil is connected
to the ignition switch through the ballast resistor,
and
is also connected directly to the starter
sole­

noid to by-pass the resistance during cranking of
engine.
The
negative (—) terminal is connected to the

distributor.
The secondary (high tension) terminal
is connected by a short cable to the center terminal
in
the distributor cap.

Always
make certain the coil wires are connected to the proper coil terminals to ensure correct
coil
polarity.

Note:
The ignition coil and ballast resistor must
be of the same manufacturer. Ballast resistors
and
ignition coils of one manufacturer are inter­changeable with both units of the other. H-32.
Ballast
Resistor

•
V-6 Engine.

An
ignition ballast resistor is in series with the
primary
winding of the coil. The ballast resistor
helps regulate the flow of
primary
current through­
out the speed range. At low
speeds
when the con­
tacts remain closed longer, the ballast heats and
increases in resistance, thereby limiting the flow of

primary
current. At higher
speeds
when the con­
tacts remain closed for shorter periods of time, the ballast
cools
and thereby decreases in resistance
to allow more
primary
current and reduce the
fall

off
in
available voltage.
During
starting, the resistor compensates for the lowered battery
voltage
re­
sulting from the starter load and permits an in­ crease in
primary
current, resulting in a higher
secondary
voltage
for starting.
The
only
test
required of the ignition ballast re­
sistor is a continuity check. Characteristics of the ballast produce wide variations in resistance with
changes in ballast temperature. Therefore, check­ ing
voltage
drop across the ballast would be mis­
leading.

Caution:
Never make a connection that connects
the ballast across the battery as this
will
burn
the ballast resistor winding.

H-33.
Spark
Plugs

Clean
and gap
spark
plugs as described in
Par.
C-4.
Inspect them for excessive burning and erosion of
electrodes, blistering of porcelain at the firing tip,

black
deposits, or fouling. These conditions indicate
that the plugs have not been operating at the cor­

rect
temperature.

Note:
Prolonged idling just before removing and
checking the plugs should be avoided as it may
produce false indications.

Spark
plug operating temperatures may have been
too hot, too cold, or normal as described.

a.
At too hot a temperature, the tip of the insulator
will
show
dark
spots
and blisters after fairly short service. As high-temperature operation is con­
tinued, the whole insulator
nose
will
discolor, show­
ing fused and blistered
deposits
near the electrode
as well as considerable erosion and burning of the
electrodes. After extreme service, the porcelain it­ self may be fused, cracked, and blistered at the tip.

The
electrodes
will
show extreme erosion and
burn­

ing and possibly even surface cracking.

Note:
If such cracking appears on certain plugs
after fairly short service, it may be caused by water
leaks in the associated cylinders.
b. At too cold a temperature plug operation, in
the early
stages,
will
result in a
dull
black
sooting

of the plug.
This
condition frequently is found in new vehicles during the break-in period and is no
indication of trouble in this case. As the condition progresses, black
deposits
of oil and carbon build
up on the base of the shell and on the insulator

until,
in extreme cases, the space
between
insulator

and
shell may be almost completely filled. Excessive
electrode erosion
will
seldom be found in cases of cold plug operation. These indications can be pro­
duced by the use of an excessively
rich
air-fuel mixture and the carburetor should be checked if
this condition is suspected. Fouling
will
also be
caused by leaking rings or intake valve
guides
that
permit excessive oil to reach the combustion
chambers.
The use of a hotter plug
will
help
burn

away
some
of this fouling but the mechanical con­ dition of the
engine
should be corrected.
c. In normal temperature operation the plug
will
accumulate grayish-tan to reddish-brown
deposits

with
fairly uniform discoloration of the insulator
nose
and slight, localized electrode erosion. If the
insulator shows any blotches, blisters,
irregular
dis­
coloration, etc., look for hot-plug symptoms. Too
hot or too cold plug operation may be caused by
the use of plugs of other than the specified heat

rating
but if the plugs are as specified a hotter or 187