fuel pressure DODGE TRUCK 1993 Service User Guide

8D
- 22
IGNITION
SYSTEMS

• (1) Disconnect the wiring and secondary cable from
the ignition coil (Figs. 9 or 10).

WARNING:
(3.9L/5.2L/5.9L
LDC-GAS ENGINES)
DO
NOT REMOVE
THE
COIL MOUNTING BRACKET-TO-
CYLINDER HEAD MOUNTING BOLTS.
THE
COIL MOUNTING BRACKET
IS
UNDER ACCESSORY
DRIVE BELT TENSION.
IF
THIS BRACKET
IS TO BE
REMOVED
FOR ANY
REASON,
ALL
BELT TENSION
MUST FIRST
BE
RELIEVED. REFER
TO THE
BELT
SECTION
OF
GROUP
7,
COOLING SYSTEM.

(2) Remove ignition coil from coil mounting
bracket (two bolts).
INSTALLATION (1) Install the ignition coil to coil bracket. If nuts
and bolts are used to secure coil to coil bracket,
tighten to 11 N«m (100 in. lbs.) torque. If the coil mounting bracket has been tapped for coil mounting

bolts,
tighten bolts to 5 N«m (50 in. lbs.) torque.
(2) Connect all wiring to ignition coil.

INTAKE MANIFOLD CHARGE
AIR
TEMPERATURE

SENSOR

REMOVAL The charge air temperature sensor is located in
right-front side of intake manifold (Figs. 11 or 12).
Fig.
11
Sensor
Location—3.9L Engine—Typical
(1) Disconnect electrical connector at sensor (Figs.
11 or 12).
(2) Remove sensor from intake manifold.
INSTALLATION (1) Install sensor to intake manifold. (2) Tighten the sensor to 13 N-m (10 ft. lbs.)
torque. (3) Install electrical connector.
Fig.
12
Sensor
Location—5.2L/5.9L

Engines—Typical
MANIFOLD ABSOLUTE
PRESSURE
(MAP)
SENSOR

For removal and installation, refer to Manifold Ab­
solute Pressure Sensor in group 14, Fuel Systems.

OXYGEN
(02)
SENSOR
For diagnostics and removal/installation proce­

dures,
refer to Group 14, Fuel Systems, in this man­

ual.
POWERTRAIN CONTROL MODULE
(PCM)
REMOVAL The PCM is located in the engine compartment be­
hind the battery and under the left front fender (Fig.

13).
DATA
UNK CONTROL
CONNECTOR MODULE
J9314-164

Fig.
13 PCM Location—Typical (1) Disconnect negative battery cable at battery.
(2) Disconnect positive battery cable at battery.
(3) Remove battery holddown clamps and remove
battery.
(4) Remove 60-way electrical connector from PCM.
(5) Remove the three PCM mounting bolts (Fig.

14).

• • ^ ^ ^ INSTRUMENT PANEL AND GAUGES 8E - 1
CONTENTS

page
CLUSTER AND GAUGE SERVICE PROCEDURES . 12
CLUSTER AND GAUGE TEST PROCEDURES .. i
GENERAL INFORMATION . 1
page

MESSAGE CENTER-DIESEL ENGINE ........ 4
MESSAGE CENTER-GAS ENGINE .......... 3

SWITCH
AND PANEL COMPONENT SERVICE . 16
GENERAL
INFORMATION
INDEX

page

Generator
Indicating
System
2
Distance
Sensor
2

Electronic
Digital
Clock
3

Fuel
Level
Indicating
System
1
page

Malfunction
Indicator
(Check
Engine)
3

Oil
Pressure
Warning
Lamp
................. 2
Speedometer/Odometer
System
2

Temperature
and Oil
Indicating
System
......... 2
D-body trucks have an instrument cluster which
includes gauges for fuel level, coolant temperature,
oil pressure, and charging system voltage (Fig. 1).
When the ignition switch is in the OFF position all
the gauges will show a reading except the voltage gauge. However, the readings are only accurate
when the ignition switch is in the ON position.
The cluster also includes warning lamps for:
• seat belt warning
• low oil pressure
• high beam
• left and right turn signals
• check engine. J908E-66

Fig.
11nstrument
Cluster
FUEL LEVEL INDICATING SYSTEM (FIG. 2)
A hinged float arm in the fuel tank raises or lowers
depending on the fuel level. The float arm contacts a
variable resistor in the gauge sending unit. This pro­
vides a change of resistance in the fuel gauge circuit
with any up or down movement of the float. This sender
resistance is shown as fuel level on the gauge. Resistance is greatest when the fuel level in the
tank is low and the float arm drops. With high resis­
tance current flow is low and consequently positions
the instrument panel gauge pointer to low.
Resistance in the circuit is at a minimum when the
tank is full and the float arm is raised. With resis­
tance at a minimum, current flow is high registering
full on the instrument panel gauge.
12
VOLTS
TO

GAUGE
IP

FUEL
TANK

SENDING
UNIT

FLOAT

SENDING
UNIT
1:
1
j
^
fCONNECTOR

!g|yj-»—
FUEL

GAUGE

FUEL

TANK

J098E-47

Fig.
2
Fuel
Level
Indicating
System

INSTRUMENT PANEL AND GAUGES

•

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
- 6
INSTRUMENT PANEL
AND
GAUGES

•
(5)
Clip float arm of sending unit to its empty stop
(Fig. 2) and turn ignition key to ON position. The
gauge should read Empty, plus one pointer width, or
minus two pointer widths.
(6) Move and clip sending unit float arm to full

stop.
The gauge should read Full, or above.
Fig. 2 Fuel Tank Sending Unit Test
RESULTS (1) If fuel gauge does not meet specifications, check
following items as possible causes; (a) Wiring and connections between the gauge
sending unit and multiple connector. (b) Wiring and connections between multiple
connector and printed circuit board terminals.
(c) Circuit continuity between printed circuit
board terminals and gauge terminals.
If these items check okay, fuel gauge is defective
and must be replaced.
(2) If the fuel gauge meets specifications check fuel
tank and original installed fuel tank sending unit as follows:
(a) Carefully remove fuel tank sending unit from
tank.
(b) Connect sending unit wire and jumper wire
as described in the procedure.
(3) If fuel gauge now checks within specifications,
originally installed sending unit is electrically okay,
check following as possible cause:
(a) Ground strap from sending unit to fuel line
for continuity. (b) Sending unit deformed. Make sure sending
unit float arm moves freely and pick up tube is not
bent so that it contacts bottom of tank. Inspect float for any signs of damage or leaks. (c) Sending unit improperly installed. Install
properly.
(d) Mounting flange on fuel tank for sending
unit deformed. Feel for interference fit of sending
unit to bottom of tank. It is permissible to bend
pick up tube down a little near mounting flange to gain interference fit.
(e) Fuel tank bottom deformed causing improper
positioning of sending unit pick up tube. Replace or
repair tank and recheck sending unit. Refer to Fuel
Tank Section of Group 14 - Fuel System.

WARNING
LAMP
SYSTEM
TESTS
LOW
OH.
PRESSURE WARNING LAMP CIRCUIT
TEST
The low oil pressure warning lamp will illuminate
when the ignition key is turned to the ON position.
The lamp also illuminates if the engine oil pressure drops below a safe oil pressure level.
To test the system turn ignition key to the ON po­
sition.
If the lamp fails to light, inspect for a broken or
disconnected wire at the oil pressure combination
unit. The combination unit is located at the rear of
the engine (Fig. 3). If the wire at the connector checks good, pull connector loose from the switch and
with a jumper wire ground connector to the engine (Fig. 4). With the ignition key turned to the ON po­
sition check the warning lamp. If lamp still fails to
light, inspect for a burned out bulb or disconnected
socket in the cluster.
If light comes on, proceed and start engine. If the
lamp remains on, immediately turn engine off and
check engine oil pressure according to procedures as
outlined in Group 9 - Engine of this manual. If the
oil pressure meets specifications, check for a
grounded wire and/or replace the oil pressure send­
ing unit (refer to combination oil unit test). Fig. 3 Oil Pressure Sending Unit—Gas Engine

INSTRUMENT
PANEL
AND
GAUGES
8E - S
J938E-34
Fig. 7 Coolant Temperature Sensor—Gas Engine
AIR
TEMPERATURE SWITCH

-
COOLANT TEMPERATURE
SWITCH

Fig. 8 Coolant Temperature Sensor—Diesel Engine

OIL PRESSURE
GAUGE
CIRCUIT
TEST
(1) Remove oil pressure gauge. Refer to Gauge Re­
placement. (2) Check for continuity in the wire between the
oil pressure sensor and the oil pressure gauge (sensor
input pin) (Figs. 10, 11, 12 and 13). (3) With the ignition switch in the ON position,
check for battery voltage across the B+ pin and the Ground pin. J908E-6i_
Fig. 9 Temperature Gauge Pins

TEMPERATURE/OIL/FUEL
GAUGE
DIAGNOSIS

GAUGE INDICATES HIGHER

OR
LOWER
THAN
ACTUAL I
FAULTY WIRING
FAULTY SENDING
UNIT*

FAULTY INSTRUMENT PANEL
GAUGE*
ERRATIC
GAUGE OPERATION
'TEST

PROCEDURES

DESCRIBED

ARE
IN
APPROPRIATE
SECTION OF

SERVICE

MANUAL

LOOSE
OR DIRTY ELECTRICAL CONNECTIONS FAULTY INSTRUMENT PANEL
GAUGE*
J908E-52

FUEL
GAUGE
CIRCUIT
TEST
(1) Remove fuel gauge assembly. Refer to Gauge
Replacement. (2) Check for continuity in the wire between the
fuel tank sending unit and the gauge (fuel level in­
put pin) (Figs. 14 and 15). (3) With the ignition switch in the ON position,
check for battery voltage across the B + pin and the Ground pin.

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.

INSTRUMENT PANEL
AND
GAUGES
8E - 13

INSTRUMENT
PANEL MAP LAMP
BRACKET
HEADLAMP
SWITCH

CLUSTER

ASSEMBLY

HEADLAMP

SWITCH
MOUNTING
NUT CARGO LAMP
SWITCH

BEZEL
AND
APPLIQUE

HEADLAMP
KNOB
AND
STEM

BRACKET-AAAP LAMP
MOUNTING

Fig.
2 Instrument
Panel
(6) Position lower steering cover and install 4
screws.

(7)
Install bezel.
(8)
Remove protective cover from steering column.
(9) Connect negative cable to battery. (10) Check to see that all instruments are func­
tioning properly.

PRINTED CIRCUIT BOARD
A visual inspection of the conductors should be
made for cracks or damaged circuits. If no visual
damage is evident, each circuit should be tested for continuity with an ohmmeter or a test light. Should an open circuit be detected, the printed circuit board
should be replaced.
REMOVAL (FIG. 3J (1) Remove instrument cluster. See cluster re­
moval.

(2)
Remove lamp socket assemblies.
(3) Remove gauge mounting screws and remove
gauges.
(4) Remove printed circuit board mounting screws.
(5)
Remove printed circuit board from cluster hous­
ing.
HEADLAMP

SWITCH
BEZEL
CLUSTER MASK AND LENS
J928E-46
Cluster
and
Switches

INSTALLATION

CAUTION:
Do not overtighten mounting
screws
or

damage
to circuit
board
and/or
cluster
housing
will

occur.

(1) Position printed circuit board on cluster hous­
ing, install mounting screws and tighten.
(2)
Install gauges.
(3) Install lamp socket assemblies. Be sure illumi­
nation lamp diffusers are installed. (4) Install instrument cluster.

FUEL GAUGE

TEMPERATURE
GAUGE VOLTAGE GAUGE
OIL
PRESSURE
GAUGE
It is not necessary to remove instrument clus­
ter from vehicle for gauge replacement. When removing gauge assemblies (Fig. 4) from
cluster, gauge must be pulled straight out, not
twisted, or damage to gauge pin and/or printed cir­ cuit board may result. (1) Disconnect negative cable from battery.

(2)
Remove bezel. Refer to Cluster Bezel Removal. (3) Remove cluster mask and lens. Refer to Cluster
Mask and Lens Removal.

8E
- 14
INSTRUMENT
PANEL
AND
GAUGES

•
VOLTAGE
GAUGE
Fig. 3 instrument Cluster Printed Circuit Board

SPEEDOMETER OIL
PRESSURE

GAUGE
TEMPERATURE GAUGE
FUEL
GAUGE

Fig. 4 Cluster With Mask Removed
J908E-69

(4)
Remove gauge mounting screws.
(5) Pull gauge rearward to remove.
For Installation, reverse Removal procedures.

SPEEDOMETER/ODOMETER
It is not necessary to remove instrument clus­
ter from vehicle for speedometer replacement. When removing speedometer (Fig. 4) from cluster,
gauge must be pulled straight out, not twisted, or
damage to gauge pin and/or printed circuit board
may result. (1) Disconnect negative cable from battery.
(2) Remove bezel. Refer to Cluster Bezel Removal.
(3) Remove cluster mask and lens. Refer to Cluster
Mask and Lens Removal. (4) Remove mounting screws retaining speedome­
ter/odometer to housing.
(5) Pull speedometer/odometer rearward to remove.
For Installation, reverse Removal procedures.

•

INSTRUMENT PANEL
AND
GAUGES
8E - 15
PRND21 INDICATOR

REMOVAL
(1) Remove bezel. Refer to Cluster Bezel Removal.

(2)
Remove cluster mask and lens. Refer to Cluster
Mask and Lens Removal. (3) Remove cluster assembly. Refer to Instrument
Cluster Removal. (4) Remove screws attaching PRND21 mechanism
to cluster housing.
(5)
Remove PRND21 mechanism.
INSTALLATION (1) Position PRND21 mechanism to cluster hous­
ing. (2) Install mounting screws.

(3)
Install cluster assembly. (4) Install mask-lens.

(5)
Install bezel.

LAMP BULBS
CLUSTER ILLUMINATION LAMPS TURN SIGNAL INDICATOR LAMPS
LOW OIL PRESSURE INDICATOR LAMP
HIGH BEAM INDICATOR LAMP CHECK ENGINE LAMP
SEAT BELT WARNING LAMP
REMOVAL (1) Disconnect negative cable from battery.
(2) Remove instrument cluster. See cluster re­
moval.
(3)
Twist lamp socket assembly and remove from
printed circuit board. (4) Remove bulb from socket.
INSTALLATION (1) Install bulb into socket.
(2) Install socket assembly into printed circuit
board.
(3)
Position cluster into place in panel. See cluster
installation. (4) Connect battery negative cable.

LAMP BULB REPLACEMENT—MESSAGE CENTER

REMOVAL (1) Disconnect battery negative cable.
(2) Remove instrument cluster bezel assembly. Re­
fer to Instrument Cluster removal.
(3)
Twist lamp socket assembly and remove from
printed circuit board. (4) Remove bulb from socket.
INSTALLATION (1) Install bulb into socket assembly. (2) Install lamp socket assembly into printed cir­
cuit board.

(3)
Install Instrument Cluster bezel assembly to
instrument panel. Refer to Instrument Cluster instal­
lation.
(4) Connect negative cable from battery.
FOUR WHEEL DRIVE INDICATOR LAMP (1) Pull bulb and socket assembly from rear of
housing. (2) Remove bulb from socket.

(3)
Reverse removal procedures to install.

SPECIFICATIONS
Fuel
Gauge Calibration
Mntar Position Resistance
Empty Graduation 90
ohms
± 3
ohms
Empty Stop
Greater
than
96.5 ohms

Full
Graduation 12 ohm
± 3
ohms

Full
Stop
Less
than
8
ohms

1/2
45.3 ohms
± 3
ohms

Temperature
Gauge
Calibration

Pointer
Position Resistance
Cold Graduation 655 ohms
Hot Graduation 64 ohms
Oil Pressure Gauge Calibration

Pointer
Position Resistance
Low Graduation 100 ohms
High Graduation 12 ohms

J908E-58

•

LAMPS
8L - 11
BULB
APPLICATION

GENERAL
INFORMATION
The following Bulb Application Table lists
the

lamp title
on the
left side
of the
column
and
part
number
on the
right.

CAUTION:
Do not use
bulbs
that
have
a
higher
can­

dle power than
the
bulb
listed
in the
Bulb
Applica­

tion Table.
Damage
to
lamp
can
result.

EXTERIOR LAMPS
Auxiliary Turn Signal (Snow Plow) 2057
Auxiliary Headlamps (Snow Plow) .6054
Back-up....................... .......1156 Cargo Lamp..
922

Clearance Lamps
194

Front Side Marker
168

Headlamp/Sealed Beam .6052
License Plate
168
Park/Turn Signal 2057
TaiyStop/Turn Signal ...2057

INTERIOR LAMPS

DIMMER CONTROLLED LAMPS Service procedures
for
most
of the
lamps
in the in­

strument panel
are
located
in
Group
8E,
Instrument
Panel
and
Gauges. Some components have lamps
that
can
only
be
serviced
by an
Authorized Service Center (ASC). These components must
be
removed
from
the
vehicle
for
service. Contact local dealer
for
location
of
nearest
ASC.
A/C Heater Control
158

Ash Receiver
..158

Gear Shift Selector...........................................PC194
Heater Control
158

Instrument Cluster.. PC 194
Radio
ASC
Snow Plow Control
.158

INDICATOR LAMPS Service procedures
for
most
of the
lamps
in the in­

strument panel,
and
switches
are
located
in
Group

8E,
Instrument Panel
and
Gauges. Anti-lock Brake PC194
Brake Warning PC194 Check Engine PC194
Engine
Oil
Pressure
158

Fasten Seat Belts.. PC 194 Four Wheel Drive ....158
Hazard Flasher
194

High Beam PC194
Low Fuel....... JPC194
Maintenance Required PC 194
Transmission Temperature ..PC 194 Turn Signal PC194
NON-DIMMING LAMPS Service procedures
for
most
of the
lamps
in the
fol­
lowing list
can be
found
in
Group
23,
Body.
Dome
1004

Engine Compartment ...105 Glove Compartment....
1891

Ignition Lock
ASC

Reading Lamp
912