
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

H
ELECTRICAL
SYSTEM H-15L SERVICE
DIAGNOSIS
SYMPTOMS
Battery
Discha
rged: Shorted
Cell
in Battery......... Short in Wiring..
•
Generator Not Charging ,
Loose or Dirty Terminals
Excessive Use of Starter Excessive Use of Lights...... Insufficient Driving.........
Low
Regulator
Setting.......
Stuck
Cut-out in Regulator. ..
Low
Electrolyte
Level
in Cells
Alternator:
FAILS
TO
CHARGE:
Belt Loose Open or High Resistance in
Charging
or Ground Return
Circuit
or Battery Connections............
Excessively Worn, Open, or
Defective
Brushes.
Open Isolation
Diode.
Open Rotor (Field
Coil)
LOW
OR
UNSTEADY
CHARGING RATE:
Belt Loose.... Intermittent or High Resistance
Charging
or Ground Return
Circuit
or Battery Connections
Excessively Worn, Sticky, or Intermittent Brushes
Shorted or Open Rectifier
Diode
Grounded
or Shorted
Turns
in Rotor (Field
Coil)
Open,
Grounded, or Shorted
Turns
in
Stator
EXCESSIVE
CHARGE RATE:
Loose Connections on Alternator...........
Faulty
Regulator
NOISY
ALTERNATOR:
Defective
or Badly Worn Belt
Misaligned Belt or Pulley
Loose Pulley
Worn
Bearings.
Shorted Rectifiers
Generator:
Low
Charging Rate—
Dirty
Commutator
Poor Brush Contact.
................
Regulator Improperly Adjusted.......
High
Resistance in Charging
Circuit...
Ground
Strap Engine to Frame Broken
Loose or Dirty Terminals Slipping Generator Belt
Worn
Out Brushes
Weak
Brush Spring Tension..........
Out
of Round Commutator
PROBABLE REMEDY
Replace Battery
Check
Wiring
Circuit
Inspect Generator and Fan Belt
Clean
and Tighten
Tune
Engine
Check
Battery
Recharge Battery
Correct
Setting
Correct
Add
Distilled Water
Tighten to
Specifications
Test
and Correct
Test
Brushes and Replace if Necessary
Test
and Replace if Necessary
Test
and Replace if Necessary
Tighten to
Specifications
Test
and Correct
Test
and Replace if Necessary
Test
and Replace if Necessary
Test
and Replace if Necessary
Test
and Replace if Necessary
Check
and Correct
Check
and Correct
Replace
Align,
Replace Parts as Necessary Tighten Replace Bearings as Necessary
Test
and Replace as Necessary
Clean
Commutator
Repair
or Install New Brushes
Adjust
Clean
and Tighten Terminals Replace
Clean
and Tighten
Adjust
Belt
Install
New Brushes
Replace
Repair
220

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL
H
H-151.
SERVICE
DIAGNOSIS—Continued
SYMPTOMS PROBABLE
REMEDY
Generator:
(continued)
Fails
To Charge-Open Charging Circuit Correct
Sticking Brushes Repair or Replace
Dirty
or Burned Commutator ... Clean Commutator
Grounded Commutator Replace
Open Circuit in Field Replace
Weak Soldering on Armature. . . Repair Grounded Wiring Repair
Defective
Regulator. .. Replace Regulator
Too High Charging Rate— Regulator Improperly Adjusted Adjust or Replace
Short in Armature Replace Grounded Field-to-regulator Wire Correct
Shorted
Cell
in Battery... Replace Battery
Starting
Motor: Slow Starter Speed— Discharged Battery or Shorted
Cell
Recharge or Repair
Ground
Strap Engine to Frame. Clean Terminals and Tighten
Loose or Dirty Terminals Clean and Tighten
Dirty
Commutator Clean with No. 00 Sandpaper
Worn
Out Brushes Install New Brushes
Weak Brush Spring Tension Replace
Worn
Bearings Replace Burned Starter Switch Contacts Replace Switch
Will
Not
Turn
Engine— Open Circuit at Starter Correct
Solenoid
Open or Stuck Replace
Solenoid
Starter Switch
Defective
Replace Switch
Starter Drive Broken or Stuck. Repair or Replace
Battery Discharged Recharge Battery
Distributor:
Hard
Starting— Distributor
Points
Burned or Pitted Clean
Points
or Replace (Adjust)
Breaker
Arm Stuck on Pivot Pin...... . ... . . . Clean and Lubricate
Breaker
Arm Spring Weak Replace
Points
Improperly Adjusted Adjust
Spark
Plug
Points
Improperly Set Adjust
Spark
Plug Wire Terminals in Distributor
Cap
Corroded Clean
Loose Terminals Check Circuit
Loose or Dirty Terminals on Ground Strap— Engine to Frame. Clean and Tighten
Condenser Faulty Replace Improper Ignition Timing Set Timing
Lights:
Burn
Dim— Loose or Dirty Terminals....... ........ Clean and Tighten
Leak
in Wires. Check Entire Circuit for Broken Insulation
Poor Switch Contact Install New Switch Poor Ground Connection Clean and Tighten
Aim
Headlamp Beams. Use Aiming
Chart
221

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL
ALPHABETICAL INDEX
SUBJECT PAR.
SUBJECT
PAR.
Abbreviations,
List
U-17 Accelerator Linkage E-70
Air
Cleaner B-25, B-26, B-82, C-21, E-69
Air
Delivery Manifold Fl-4, F2-12
Air
Filter, Pump • F2-3, F2-11
Air
Injection Tubes Fl-5, F2-13
Air
Pump Fl-2, F2-10
Alternator Bearings B-76, H-80
Alternator Brushes H-74, H-75
Alternator Charging System •
•
H-63
Alternator
Diodes
H-69, H-85
Alternator Precautions H-64 Alternator Rotor H-76, H-79
Alternator Tests H-67, H-77 Alternator Specifications H-l 52
Alternator Stator H-84
Anti-Backfire
Valve Fl-6, F2-14
Antifreeze
Chart
• G-22 Antifreeze
Solutions
- G-16
Axle Camber O-l
Axle Caster 0-8
Back-Up
Lights H-135
Ballast
Resistor. H-32 Battery C-3, H-2 Bendix Folo-Thru Drive H-105, H-106
Bleeding Brakes P-7
Body T-l Body Lubrication. B-65 Body Name Plates ' A-7
Brake
Adjustment P-14
Brake
Drums. • .P-17
Brake
Hoses
P-8
Brake
Maintenance . P-5
Brake
Master Cylinder B-40, P-2, P-20
Brake
Service P-6
Brake
Wheel Cylinder • P-21
Camber
Adjustment 0-7
Camshaft D-6, D-51, D-52, D-53, D-81, Dl-26, Dl-33, Dl-55, Dl-80
Carburetor
E-10, E-25
Carburetor
Adjustment C-25, E-14, E-40,
Fl-13,
F2-16
Carburetor
Specifications .Fl-38, F2-34, E-79
Caster
Adjustment 0-8
Charging
System Service. .H-34, H-63
Chassis
Lubrication B-7, B-83
Chassis
Torque Specifications U-14
Clutch
1-4, MO
Clutch
Adjustment 1-3
Clutch
Linkage B-44, 1-3
Clutch
Maintenance .. 1-2
Clutch
Release Bearing B-74, 1-25
Coil
C-20, H-19, H-31 Connecting Rod Bearings D-47, D-48, D-49, Dl-49 Connecting Rod
Crank
Pins D-42
Connecting Rods... .D-20, D-50, D-95, Dl-31, Dl-45, Dl-75
Controls B-59, B-62
Cooling System B-28, G-l Cooling System Filling G-2
Core
Hole Expansion Plugs D-72
Crankcase
Ventilating System B-13, C-6, D-110
Crankshaft
D-26, D-38, D-39, Dl-38, Dl-73
Crankshaft
End Play. D-83, Dl-74
Crankshaft
Main Bearing D-43, D-44, Dl-32, Dl-40, Dl-73
Crankshaft
Oil Seal, Front Dl-21, Dl-85
Crankshaft
Oil Seal, Rear D-63, D-85, Dl-72
Cylinder
Block D-32, Dl-34
Cylinder
Bores D-35, Dl-36
Cylinder
Head D-17, D-73, D-98, Dl-24, Dl-63, Dl-82
Cylinder
Head Torque. C-5
Dash Pot Adjustment C-26, E-44
Differential B-51 thru B-53, N-9 Differential Adjustments N-16, N-18
Differential, Powr-Lok N-20
Differential,
Trac-Lok
N-24
Directional Signal Lights. . H-138
Distributor B-14, B-15, C-10, D-13, Dl-9, H-9, H-20 Distributor Check H-l7, H-28
Distributor Point Dwell C-17 Distributor Resistance Test C-16
Drawbar
.R-6, U-16
Dual
Brake System P-l thru P-26
Electrical
Instruments H-l22
Electrical
Specifications .H-l52
Electrical
System H-l Engine .
..D-l,
Dl-1
Engine Code Number A-6
Engine Compression .
.
C-9 Engine Disassembly . • .D-6, Dl-5 Engine Installation D-105, Dl-102
Engine Lubrication System B-4, B-6 Engine Mountings D-3, Dl-3
Engine Oil B-9
Engine Oil Filter B-10, B-ll,
D-lll,
Dl-13, Dl-93
Engine Oil Pan D-l9, D-66, D-97, Dl-29, Dl-51, Dl-77 Engine Oil Pump. . .D-14, D-65, D-93, Dl-19, Dl-50, Dl-87
Engine Overheating. G-l9 Engine Removal D-5, Dl-4.
Exhaust
Emission Control — F4 Fl-1 thru Fl-30
Exhaust
Emission Control — V6 F2-1 thru F2-36
Exhaust
Manifold, Install F-6
Exhaust
Pipe -
•
F-8
Exhaust
System F-2, F-3
Exhaust
System Maintenance F-4
Fan
Belt C-27, Dl-11, Dl-96, G-18
Floating Oil Intake. D-64, Dl-30, Dl-50, Dl-76 Flywheel D-25, D-67, D-87, Dl-28, Dl-52, Dl-78
Flywheel Housing. D-71, D-88, Dl-27, Dl-54, Dl-79
Flywheel Pilot Bushing D-70, 1-8
Frame
R-l
Frame
Alignment. R-2
Frame
Dimensions R-3
Frame
Straightening R-4
Front
Bumper Weight. • U-9
Front
Axle B-50, M-2
Front
Axle Alignment R-5
Front
Axle Installation • M-12
Front
Axle Maintenance M-3
Front
Axle Shaft Removal M-5
Front
Axle U-Joint B-54, B-55, M-7
Front
Axle Steering Knuckle M-&
Front
Wheel Alignment 0-4
Front
Wheel Bearings B-56, B-57, Q-4
Front
Wheel Toe-in 0-5, 0-6
Front
Wheel Turning Angle 0-9
Fuel
Gauge Float Unit F-76
Fuel
Lines - E-77
Fuel
Pump E-45, E-54, E-60, E-67
Fuel
Pump Check C-23
Fuel
Tank
E-72
G
Gauges, Testing H-l24
General
Specifications A-8
Generator B-16, H-34 thru H-40
Glass
Replacement • T-4
Governor. . .
•.
• U-3
Guides, Valve D"61
H
Hazard
Warning Lights H-139
Head Lamp Aiming H-131, H-132 Head Lamp Replacement H-130
Headlight Dimmer Switch H-l
2
7
Heat Control Valve C-7, F-7 Heated Air System • •
•
F2-2
Heater U-10
Horns.....
....H-137 371