fuel pump DODGE TRUCK 1993 Service Repair Manual

0 - 6
LUBRICATION
AND
MAINTENANCE
GASOLINE ENGINE MAINTENANCE SCHEDULE

HEAVY
DUTY
CYCLE

Inspection and service is also necessary anytime
a
malfunction is observed or suspected.
When both
time
and mileage
are
Miles (Thousand)

shewn,
follow
the
interval

which occurs first. Kilometers (Thousand) 6
12 18 24
30 36 42 48 54
60 66 72

78
82V2
84 90
96
102 108
When both
time
and mileage
are
Miles (Thousand)

shewn,
follow
the
interval

which occurs first. Kilometers (Thousand) 9.6 19 29
38 48 58 67 77
85 96 106 116
125 132
135
145
154 164
174

Coolant
Condition, Coolant
Hoses/Clamps
X
X X X
X X X X
X X X X
X X X
X X X

Exhaust
System
—
Check
X X X X X X X X X X X
X X X X X
X X

Oil
—
Change
(6
Months)
X X X X X X X
X X

X
X
X

X X X

X X
X

Oil
Filter
—
Change (2nd
Oil
Change)
X X X X
X X
X X
X

Drive Belt Tension
—
Inspect
&
Adjust
X' X
X1

X X' X

Drive Belts (V-Type)
—
Replace
X

Air
Filter/Air
Pump
Air
Filter
—
Replace
X X X
X

Crankcase
Inlet
Air
Filter
(6 &
8
Cyl.
Eng.
Only)
—
Clean
X X
X X

Spark
Plug
—
Replace
X X X

Fuel
Filter
—
Replace as necessary

Coolant
—
Flush/Replace
(36
months)
& 24
months/48
000 km

(30,000
miles)
thereafter
X
EGR
Valve
&
Tube
—
Replace X2

EGR
Tube
—
Clean Passengers
X2
PCV
Valve
—
Replace X2

Vacuum
Emission
Components
—
Replace
X

Ignition Timing
—
Adjust
to
Specs,
as necessary X
Ignition Cables, Distributor Cap
&
Rotor
—
Replace
X

Manifold Heat Control Valve
—
Lubricate
X

Battery
—
Replace X

Oxygen
Sensor
—
Replace
X2

1 For California vehicles, this maintenance is recommended
by
Chrysler Motors
to the
owner but, is not
required
to
maintain the
warranty
on the
air
pump drive
belt.

2 Requires
Emission
Maintenance Reminder Light.
If
so equipped, these parts
are to be
replaced
at the
indicated mileage,
or
when the
emissions
maintenance reminded light remains on continuously
with
the key in the
"on" position, whichever occurs first.
J9100-20

DIESEL
ENGINE
MAINTENANCE
SCHEDULE
HEAVY
DUTY
CYCLE
Inspection
and
service
is
also
necessary
any
time
a
malfunction
is
observed
or
suspected.

Iff both
time
and distance Miles (Thousand)
are listed, use the
interval

that
ends
first. Kilometers (Thousand) 6
12
18 24
30 36 42

4S
54
60 66
72 78
84 90 96
102 108
Iff both
time
and distance Miles (Thousand)
are listed, use the
interval

that
ends
first. Kilometers (Thousand) 9,6 19
29
38 48 58 67

77

85 96 106
116 125 135 145 154
164 174

Coolant
Condition, Coolant
Hoses/Clamps
(12 months)

Coolant
Flush/Replace (36 months) & 24 months/
48 000 km
(30,000
miles)
thereafter
O

Oil—Change
(6 months)
X X X
X X X
X X X X X
X X X X X X
X

Oil Filter—Replace (Every Oil Change)
X X X
X X X
X X
X X X
X
X X X X
X X

Drive Belts—Replace
As
Necessary
X X
X X X X

Air Filter—Replace
X X
X X

Air Filter—Clean (California Only) e

®

• •
Air
Filter
Canister—Clean
o o o
o

Fuel Filter—Service When Necessary

Injection
Pump
Timing & Engine Idle Speed—

Check
& Adjust
©

• 9 • • •
Underhood Rubber/Plastic Components—Inspect/Replace • • • • •

X
— All vehicles
O
— All
vehicles
except
California.
Recommended
for
California.
•
— California only.
Recommended
for all vehicles.

0 - 14
LUBRICATION
AND
MAINTENANCE

•
ENGINE
MAINTENANCE

INDEX

page
Air
Injection
Systems/Air Pump
. 17

Air-Conditioner
Compressor
21
Battery
19

Cooling System
15

Crankcase
Ventilation
System
17
Diesel Engine
Air Filter
Canister
17

Drive Belts
20
Engine
Air
Cleaner
Filter
Element
16

Engine Break-In
14

Engine
Oil 14

Engine
Oil
Change
and Filter
Replacement
15

Exhaust Gas
Recirculation
(EGR) System
...... 19
page
Exhaust
Manifold
Heat
Control
Valve
. 17
Exhaust System
, 21

Fuel System
18

Hoses
and
Fittings
16
Ignition
Cables,
Distributor
Cap and
Rotor
...... 19

Ignition
Timing
. 19

Oxygen
(02)
Sensor
19
Rubber/Plastic Components
20

Spark Plugs
. 19

Throttle
Control
Linkage
18

Vacuum Operated, Emission
Control
Components
19

ENGINE BREAK-IN
After first starting a new engine, allow it to idle
for 15 seconds before shifting into a drive gear. Also:
• Drive the vehicle at varying speeds less than 88
km/h (55 mph) for the first 480 km (300 miles).
• Avoid fast acceleration and sudden stops.
• Do not drive at full-throttle for extended periods of
time
• Do not drive at constant speeds
• Do not idle the engine excessively A special break-in engine oil is not required. The
original engine oil installed is a high quality lubri­
cant. New engines tend to consume more fuel and oil un­
til after the break-in period has ended.

ENGINE
OIL SPECIFICATIONS

API SERWICE
GRADE
Use an engine oil that conforms to API Service
Grade S5 SG/CD or SG/CE. MOPAR®provides engine
oils that conform to all of these service grades.

SULFATED ASH—DIESEL ENGINES
Oils that contain an excessive amount of sulfated
ash can cause deposits to develop on Diesel engine
valves. These deposits can result in valve wear.

SAE
WISC0SITY
An SAE viscosity grade is used to specify the vis­
cosity of engine oil. SAE 30 specifies a single viscos­
ity engine oil.
Engine oils also have multiple viscosities. 10W-30

<
5W-30

1
1 1

F
-20 0 10 20 32 60 80 100

C
-29 -18 -12 -7 0 16 27 38
ANTICIPATED
TEMPERATURE RANGE BEFORE
NEXT
OIL
CHANGE
J9000-39

Fig.
1 Temperature/Engine Oil Viscosity—Gasoline
Engines

-12°C
-18°C 10°F
0°F- 15W-40

-23°c(^-10eF

I
10W-30
WITH
WITHOUT
BLOCK HEATER
BLOCK
SYNTHETIC
OIL

HEATER
10W-30 5W-30

J9100-29

Fig.
2 Temperature/Engine Oil Viscosity—Diesel
Engines

ENERGY
G0NSERWING
OIL
An Energy Conserving type oil is recommended for
gasoline engines. They are designated as either EN­
ERGY CONSERVING or ENERGY CONSERVING

II.
OIL
LEVEL
INDICATOR (DIPSTICK)

GASOLINE ENGINES
The engine oil indicator is located at the right
front of the engine.

•

LUBRICATION
AND
MAINTENANCE
0 - 15
DIESEL
ENGINES

The Diesel engine oil level indicator is located at
the left center of the engine, above the
fuel
injection

pump (Fig. 3).

Fig.
3
Diesel
Engine
Oil
Dipstick

ACCEPTABLE
OIL
LEVEL
To maintain proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
For gasoline engines, the acceptable levels are indi­ cated between the ADD and
FULL
marks on oil
dip­
stick. For Diesel engines, the acceptable levels are
indicated between the L (low) and H
(high) marks
on
oil dipstick. The oil level should be checked periodically. The
vehicle should be on a level surface. Wait for
five
minutes after stopping the engine. For gasoline en­
gines,
add oil only when the level indicated on the
dipstick is at or below the ADD mark. For Diesel en­
gines,
add oil only when the level indicated on the
dipstick is between the L and H marks.
Never oper­
ate a Diesel
engine when
the oil
level
is below
the L mark. The distance between the L and H
marks represents 1.9L (2 Qts) engine oil.

CAUTION:
Do not
overfill
an
engine crankcase
with

oil. This
will
cause
oil
aeration
and
result
in a de­

crease
in the
engine
oil
pressure.
ENGINE
OIL
CHANGE AND FILTER REPLACEMENT

WARNING: PROTECTIVE CLOTHING
AND
GLOVES SHOULD
BE
WORN. EXPOSED SKIN SHOULD
BE

WASHED
WITH
SOAP
AND
WATER
TO
REMOVE
USED
ENGINE
OIL.
DO NOT
USE
GASOLINE, THIN­
NER,
OR
SOLVENTS
TO
REMOVE ENGINE
OIL

FROM
SKIN.
DO NOT
POLLUTE. DISPOSE
OF
USED
ENGINE
OIL
PROPERLY.
ENGINE
OIL
FILTER

All engines are equipped with a throw-away type
oil filter. The same type of filter is recommended
when the filter is changed.

OIL CHANGE
AND
FILTER
REPLACEMENT
Bring engine up to normal operating temperature.
A more complete drainage of oil will result.
(1) Remove the drain hole plug and drain the en­
gine oil from the crankcase.
(2) Install the drain hole plug with a replacement
gasket. For gasoline engines, the oil filter should be
replaced during every second engine oil change.
For Diesel engines, the oil filter should be re­
placed during every engine oil change.
(3) Rotate the oil filter counterclockwise to remove
it.
(4) Clean the engine cylinder block oil filter boss. (5) Apply a light coat of new engine oil to the rub­
ber seal on the oil filter.
(6) Install and hand tighten the oil filter 1/2 to 3/4
of a turn clockwise. (7) Add new engine oil at the fill hole location on
top of the engine cylinder head cover. Wipe off any spilled oil.
(8) Observe the oil level on the dipstick.

CAUTION:
Do not
overfill
the
engine crankcase
with

oil.
(9)
Start the engine. Observe the oil pressure
gauge or warning lamp (as applicable). If the oil
pressure does not increase, stop the engine immedi­ ately. Check oil level.

COOLING SYSTEM

WARNING:
USE
EXTREME CAUTION WHEN
THE
ENGINE
IS
OPERATING.
DO NOT PUT
YOUR
HANDS NEAR
THE
DRIVE BELT(S), PULLEYS
OR
FAN BLADE.
DO NOT
STAND
IN A
DIRECT LINE
WITH
THE FAN
BLADE.

INSPECTION SCHEDULE
Determine the coolant level. Inspect the cooling
system hoses/clamps after each service interval has
elapsed.

COOLANT LEVEL
It is recommended that the engine coolant level be
inspected at least once a month during periods of hot
weather.
With the engine at normal operating temperature,
check the coolant level in the coolant reserve tank.
The coolant level must be at least above the ADD mark. Add coolant to the coolant reserve tank only.

5
- 4
BRAKES

• (3) During road test, make normal and firm brake
stops in 25-40 mph (40-64 Km/h) range. Note faulty
brake operation such as pull, grab, drag, noise, low
pedal, etc.
(4) Inspect suspect brake components and refer to
problem diagnosis information for causes of various
brake conditions.

COMPONENT
INSPECTION
Fluid leak points and dragging brake units can usu­
ally be located without removing any components. The
area around a leak point will be wet with fluid. The
components at a dragging brake unit (wheel, tire, rotor)
will be quite warm or hot to the touch.
Other brake problem conditions will require compo­
nent removal for proper inspection. Raise the vehicle and remove the necessary wheels for better visual ac­

cess.

DIAGNOSING BRAKE
PROBLEMS

PEDAL FALLS
AWAY
A
brake pedal that falls away under steady foot
pressure is the result of a system leak. The leak
point could be at a brakeline, fitting, hose, or caliper. Internal leakage in the master cylinder caused by
worn or damaged piston cups, may also be the prob­ lem cause.
If leakage is severe, fluid will be evident at or around
the leaking component. However, internal leakage in
the master cylinder may not be physically evident. Re­ fer to the cylinder test procedure in this section.

LOW PEDAL
If a low pedal is experienced, pump the pedal sev­
eral times. If the pedal comes back up, worn lining
and worn rotors or drums are the likely causes.
A decrease in fluid level in the master cylinder res­
ervoirs may only be the result of normal lining wear.
Fluid level can be expected to decrease in proportion to wear. It is a result of the outward movement of
caliper and wheel cylinder pistons to compensate for
normal wear. Top off the reservoir fluid level and
check brake operation to verify proper brake action.
SPONGY PEDAL. A spongy pedal is most often caused by air in the sys­
tem. Thin brake drums or substandard brake lines and
hoses can also cause a spongy pedal. The proper course
of action is to bleed the system and replace thin drums and suspect quality brake lines and hoses.

HARD PEDAL
OR
HIGH
PEDAL
EFFORT
A hard pedal or high pedal effort may be due to
lining that is water soaked, contaminated, glazed, or
badly worn. The power booster or check valve could also be faulty. On diesel engine models, high pedal effort may be
the result of a low vacuum condition. If the booster and check valve are OK, the problem may be related
to a vacuum pump hose, hose connection, hose fit­
ting, pump diaphragm, or drive gear. Vacuum pump output can be checked with a standard vacuum
gauge. Vacuum output should range from 8.5 to 25 inches vacuum. If vacuum pump output is within

limits,
check the power booster and check valve as
described in this section.

BRAKE DRAG
Brake drag occurs when the lining is in constant
contact with the rotor or drum. Drag can occur at
one wheel, all wheels, fronts only, or rears only. It is a product of incomplete brakeshoe release. Drag can
be minor or severe enough to overheat the linings,
rotors and drums.
Brake drag can also effect fuel economy. If undetec­
ted, minor brake drag can be misdiagnosed as an en­ gine or transmission/torque converter problem.
Minor drag will usually cause slight surface charring
of the lining. It can also generate hard spots in rotors and drums from the overheat-cool down process. In most

cases,
the rotors, drums, wheels and tires are quite
warm to the touch after the vehicle is stopped.
Severe drag can char the brake lining all the way
through. It can also distort and score rotors and drums to the point of replacement. The wheels, tires and brake components will be extremely hot. In se­
vere cases, the lining may generate smoke as it chars
from overheating.
Some common causes of brake drag are:
• seized or improperly adjusted parking brake cables
• loose/worn wheel bearing
• seized caliper or wheel cylinder piston
• caliper binding on corroded bushings or rusted
slide surfaces
• loose caliper mounting bracket
• drum brakeshoes binding on worn or damaged sup­
port plates
• misassembled components. If brake drag occurs at all wheels, the problem may
be related to a blocked master cylinder return port, or faulty power booster that binds and does not release.

BRAKE FADE
Brake fade is a product of overheating caused by
brake drag. However, brake overheating and subse­ quent fade can also be caused by riding the brake
pedal, making repeated high deceleration stops in a short time span, or constant braking on steep moun­
tain roads. Refer to the Brake Drag information in
this section for additional causes.

PEDAL
PULSA
TION
Pedal pulsation is caused by components that are
loose, out of round, or worn beyond tolerance limits.

•

IGNITION
SYSTEMS
8D - 5

THROTTLE
^
BODY
u

BRACKET
y^SUPPORT
BRACKET
/ |

CHARGE
AIR

ijmmmmk
TEMPERATURE
SENSOR
THROTTLE

BODY

Fig.
9
Sensor
Location—3.9L Engine—Typical
INTAKE MANIFOLD
'b AIR TEMPERATURE

SENSOR

J9314-162

Fig.
10
Sensor
Location—5.2L/5.9L
Engines—Typical
start-up (cranking) and to engine load while the en­
gine is running. The PCM uses this input, along with
inputs from other sensors, to adjust air-fuel mixture.
For more information, refer to Group 14, Fuel Sys­
tem.
The MAP sensor is mounted to the throttle body
(Fig. 11). It is connected to the throttle body with an
L-shaped rubber fitting and to the PCM electrically. For component testing, refer to the Diagnostics/Ser­
vice Procedures section of this group. For removal and installation of this component, re­
fer to the Component Removal/Installation section of
this group.

POWERTRAIN CONTROL MODULE
(PCM) The powertrain control module (PCM) is located in
the engine compartment behind the battery (Fig. 12).
The PCM was formerly referred to as the SBEC or engine controller. The ignition system is controlled by the PCM. Base ignition timing by rotation of distributor
is not adjustable.
MANIFOLD

ABSOLUTE
PRESSURE
SENSOR

TORQUE CONVERTER CLUTCH RELAY
ELECTRICAL
Jlp^

CONNECTOR
^gis!—

Fig.
11 MAP Sensor—Typical
A/C
CLUTCH RELAY STARTER RELAY
AUTO
SHUTDOWN RELAY FUEL PUMP RELAY
DATA LINK
CONNECTOR POWERTRAIN
CONTROL
MODULE
J9314-164

Fig.
12 PCM Location—Typical The PCM opens and closes the ignition coil ground
circuit to operate the ignition coil. This is done to ad­
just ignition timing, both initial (base) and advance, for changing engine operating conditions.
The amount of electronic spark advance provided
by the PCM is determined by five input factors: Cool­ ant temperature, engine rpm, intake manifold tem­
perature, manifold absolute pressure and throttle
position.
For removal and installation of this component, re­
fer to the Component Removal/Installation section of
this group.
For diagnostics, refer to the appropriate Powertrain
Diagnostic Procedures service manual for operation
of the DRB II scan tool.

THROTTLE
POSITION
SENSOR
The sensor is mounted on the throttle body (Fig.

13).
It is connected to the throttle blade shaft. The
sensor is a variable resistor. It provides the power-
train control module (PCM) with an input signal (voltage) that represents throttle blade position. As

8D
- 18
IGNITION
SYSTEMS

•
COMPONENT REMGWAL/INSTALLATION

INDEX

page

Automatic
Shut Down (ASD) Relay
18
Camshaft
Position
Sensor
, 18

Crankshaft Position
Sensor
18
Distributor
Service
20
Engine
Coolant Temperature
Sensor
20

General
Information
18
Ignition
Coil
21
page

Intake
Manifold Charge
Air
Temperature
Sensor
. 22

Manifold Absolute Pressure (MAP)
Sensor
..... 22

Oxygen
(02)
Sensor
22
Powertrain
Control
Module (PCM)
22

Spark
Plug Secondary Cables
24

Spark
Plugs
23

Throttle
Position
Sensor
(TPS)
24

GENERAL
INFORMATION
This section
of the
group, Component Removal/In­
stallation, will discuss
the
removal
and
installation
of ignition system components. For basic ignition system diagnostics
and
service
adjustments, refer
to the
Diagnostics/Service Proce­
dures section
of
this group. For system operation
and
component identification,
refer
to the
Component Identification/System Opera­
tion section
of
this group.

AUTOMATIC
SHUT DOWN
(ASb)
RELAY
The automatic shut down
(ASD)
relay
is
located
in

the engine compartment
(Fig. 1).
TORQUE CONVERTER
CLUTCH RELAY
A/C
CLUTCH RELAY STARTER RELAY

AUTO
SHUTDOWN RELAY FUEL PUMP RELAY DATA UNK
CONNECTOR POWERTRAIN
CONTROL
MODULE
J9314-164

Fig.
1
Auto
Shut Down
Relay
REMOVAL

(1) Disconnect negative battery cable
at
battery.

(2)
Remove
the
relay
by
pulling from connector.

INSTALLATION
(1) Check
the
terminals
in the
relay connector
for

corrosion
or
damage before installation.

(2)
Push
the
relay into
the
connector.

CAMSHAFT POSITION SENSOR
The camshaft position sensor
is
located
in the
dis­
tributor
(Fig. 2).
REMOVAL

Distributor removal
is not
necessary
to
remove
camshaft position sensor.

CAMSHAFT POSITION
SENSOR
SYNC

SIGNAL

GENERATOR
DISTRIBUTOR
ASSEMBLY
J9314-82

Fig.
2
Camshaft Position Sensor—Typical
(1) Disconnect negative battery cable
at
battery.

(2)
Remove distributor
cap
from distributor
(two

screws).
(3) Disconnect camshaft position sensor wiring
harness from main engine wiring harness.
(4) Remove distributor rotor from distributor shaft.

(5)
Lift
the
camshaft position sensor assembly from
the distributor housing
(Fig. 2).

INSTALLATION
(1) Install camshaft position sensor
to
distributor.
Align sensor into notch
on
distributor housing.
(2)
Connect wiring harness.
(3) Install rotor.
(4) Install distributor
cap.
Tighten mounting
screws.

CRANKSHAFT
POSITION SENSOR
REMOVAL The sensor
is
bolted
to the top of the
cylinder block
near
the
rear
of
right cylinder head
(Fig. 3).

•

INSTRUMENT PANEL
AND
GAUGES
8E - 5
CLUSTER
AND
GAUGE TEST
PROCEDURES

INDEX
page
Fuel Gauge
Circuit
Test
9

Fuel Tank Sending
Unit
Test
5

Oil Pressure Gauge
Circuit
Test
..............
9
Sending
Unit
(Sensor) Test
5
page
Speedometer
10

Temperature
Gauge
Circuit
Test
8
Voltage Gauge
Circuit
Test
10

Warning Lamp System Tests
6

CAUTION:
Disconnect
battery
negative cable,
in
en­

gine compartment, before servicing instrument panel. When power
is
required
for
test purposes,
connect
battery
cable
(for
test only).

Disconnect battery negative cable after test
and before continuing service procedures.

SENDING
UNIT
(SENSOR) TEST
When
a
problem occurs with
a
cluster gauge,
be­

fore disassembling
the
cluster
to
check
the
gauge, check
for a
defective sending unit (sensor)
or
wiring.
(1) Sending units
and
wiring
can be
checked
by

grounding
the
connector leads,
at the
sending unit,
in
the
vehicle.

CAUTION:
When connecting
an
input
terminal
to

ground,
Do Not
leave
the
connection grounded
for
more than
a
few
seconds.

(2) With
the
ignition
in the ON
position;
a

grounded input will cause
the oil,
fuel
or
tempera­
ture gauge
to
read
at or
above maximum.
FUEL TANK SENDING
UNIT
TEST

(1) Disconnect wire from terminal
on
fuel tank
sending unit (Fig.
1).

FUEL PUMP SUPPLY
INPUT
TO
GAUGE
SENDING
UNIT
GROUND
FUEL PUMP GROUND
J928E-49

Fig.
1
Fuel
Tank
Sending
Connector
Terminals
(2) Connect wire
to a
known good sending unit.
(3) Connect
a
jumper wire between sending unit
fuel pick
up
tube
and a
good ground.
(4) Check fuel gauge
as
described
in
following

steps.
Allow
at
least three minutes
at
each test point
for gauge
to
settle. Lightly tapping instrument clus­
ter
may
help position pointer.

FUEL GAUGE SYSTEM DIAGNOSIS
FUEL GAUGE SYSTEM DIAGNOSIS FUEL GAUGE

DOES
NOT

READ
FULL FAULTY PRINTED
CIRCUIT BOARD FUEL GAUGE
INOPERATIVE OR ERRATIC FUEL GAUGE
INACCURATE

E

1

I

CHECK
FAULTY WIRING
OR
TANK DEFORMED
TANK
NOT
FULL COMPONENTS
CHECK
CHECK
ALL WIRING INCLUDING GROUND
i

FAULTY FUEL GAUGE SENDING
UNIT
i 1
FUEL
C
1
DOES
1
READ
1
pAUGE
I

>N0?
1

EMPTY
1

r

TANK
NOT
EMPTY
CHECK
PROPER
ALIGNMENT
OF PICKUP AND

SENDER
ASSEMBLY.

REFER
TO
GROUP
14
FAULTY FUEL
GAUGE

J908E-74

8E
- 10
INSTRUMENT
PANEL
AND
GAUGES

GROUND
OIL
PRESSURE

SENSOR
INPUT

J908E-70

Fig.
10 Oil Pressure
Sending
Unit—Gas Engine

STEERING
PUMP
ENGINE
BLOCK

J9119-74

Fig.
11 Oil Pressure
Sending
Unit—Diesel Engine
SENDING
UNIT
(GAUGE)

SWITCH
(LIGHT)
898E-2

Fig.
12 Combination Oil Unit Terminals

VOLTAGE
GAUGE
CIRCUIT
TEST
(1) Remove voltage gauge. Refer to Gauge Replace­
ment.
Fig.
13 Oil Pressure
Gauge
Pins

r— FUEL
PUMP
SUPPLY

0 INPUT TO
GAUGE
-SENDING
UNIT
GROUND

-FUEL
PUMP
GROUND
J928E-49

Fig.
14 Fuel Tank
Sending
Connector Terminals

FUEL
GAUGE
INPUT

^
GROUND
y
J908E-71

Fig.
15 Fuel
Gauge
Pins

(2) With the ignition switch in the ON position,
check for battery voltage across the B+ pin and the Ground pin (Fig. 16).
The instrument panel voltmeter indicates elec­
trical system battery voltage.

SPEEDOMETER
(1) Remove speedometer assembly. Refer to Gauge
Replacement.

AUDIO SYSTEMS
CONTENTS

SERVICE
PROCEDURES
page

.. 7
TEST PROCEDURES
page

.. 2

GENERAL
INFORMATION
For operation of the factory installed radios, refer
to the Owner Manual supplied with the vehicle. When connecting or disconnecting the Ignition Off
Draw (IOD) connector, it is important that the igni­
tion switch be in the OFF position. Failure to place the ignition switch in the OFF po­
sition can cause the radio display to become scram­
bled when the IOD is disconnected. Connecting the IOD will correct the scrambled display.

INTERFERENCE
ELIMINATION
Many components are used on vehicles equipped
with a radio to suppress radio frequency interference (static). A capacitor is mounted inside the generator and
ground straps are utilized from cab to box and from
the engine to cowl. The previously mentioned Capacitor and Ground
Straps should be securely mounted to a clean ground
surface to work effectively. Radio resistance spark plug wires complete the in­
terference suppression system. Faulty or deteriorated spark plug wires should be replaced.
RADIO NOISE DIAGNOSIS

Noise,
Static
Hash,
Etc.

Check
For Noise in
the
Following
Positions:

1.
Accessory (All Electrical
Accessories
Off)

2. Engine Running
Is

'Static/NoiseS

Present
'With
Ign.
Key in Acc.
Yes\^|j
Accessories/
Off

No

Refer
to

Antenna

Diagnosis


f

Stop
No

Is
Static/Noise Present
With Engine
Running?.
Yes

J928F-3
Check
Following:

A.
Electric
Fuel
Pump
B.
Ignition
System
Faults

C.
Faulty Ground Connections
D.
Faulty Electronic Voltage Reg.

E.
Tighten Antenna Mounting Nut

WINDSHIELD
WIPER MOTOR
TO RIGHT
HEADLAMP
PARK/TURN
SIGNAL LAMP TO FUSIBLE LINK
CIRCUITS
TO VEHICLE SPEED
CONTROL SEE VIEW
Z

EEMC

RELAY
LEFT
HEADLAMP
GROUND
ENGINE
STARTER
A/C RELAY

COMPRESSOR

CLUTCH RELAY AUTOMATIC SHUT
DOWN RELAY
FUEL PUMP RELAY
BULKHEAD
DISCONNECT
A/C

LOW
PRESSURE
SWITCH

SIDE
MARKER LAMP
TO UNDERHOOD LAMP WIRING
VEHICLE

SPEED
CONTROL
SERVO
POWERTRAIN
CONTROL MODULE
A/C

CYCLING SWITCH TO BLOWER
MTR &

WINDSHIELD
WASHER
MTR

VIEW
IN
DIRECTION OF ARROW
Z
VIEW
IN
DIRECTION
OF ARROW
W a
o
>
o 30
>
2
m
J938W-99
Fig.
17
Engine
Compartment Wiring 3.9L, 5.2L, and 5.9L Gas
Engines