service DODGE TRUCK 1993 Service Repair Manual

8E
- 2
INSTRUMENT PANEL
AND
GAUGES

•
TEMPERATURE AND
OIL
INDICATING SYSTEM
(FIG.
3) The operation of the temperature and oil pressure
indicating systems are identical. In the temperature
system the sending unit resistance varies in direct
relationship to the temperature of the coolant. When the engine is cold, the resistance of the tem­
perature sending unit is high and a cold temperature
will be indicated on the gauge. When the engine is hot, the resistance of the tem­
perature sending unit is low and a hot temperature
will be indicated on the gauge. In the oil pressure indicating system the sending
unit resistance is actuated by a diaphragm as the oil
pressure increases or decreases. Low oil pressure causes high resistance. High pressure causes low re­
sistance. 12
VOLTS
TO
GAUGE
TEMPERATURE/
OIL GAUGE
TEMPERATURE/OIL SENDING
UNIT
J908E-48
Fig. 3 Temperature/Oil indicating System

OIL
PRESSURE
WARNING LAMP
The oil pressure warning switch, mounted on the
engine, is controlled by engine oil pressure. When engine oil pressure is normal, the switch is
held in the OFF or OPEN position. This stops cur­
rent from flowing to the oil pressure warning lamp
on instrument panel. When the engine oil pressure is low, the switch is
in the ON or CLOSED position. This allows current
to flow to the oil pressure warning lamp in the in­ strument cluster causing the warning lamp to illumi­

nate.
GENERATOR
INDICATING
SYSTEM
(FIG. 4)
The voltmeter gauge senses the voltage of the elec­
trical system.
VOLTAGE
/*

GAUGE
P/
J908E-49 Fig. 4 Generator Indicating System

SPEEDOMETER/ODOMETER SYSTEM
The speedometer/odometer system consists of an
electric speedometer and pushbutton reset odometer
mounted in the cluster. The system also includes the
wire harness from the cluster to the distance sensor at the transmission, and the adapter and pinion in
the transmission. The speedometer/odometer has the same appearance as a conventional version but it
eliminates the cable-driven mechanical system. A signal is sent from a transmission mounted distance
sensor to the speedometer/odometer circuitry through
the wiring harness. By eliminating the speedometer cable, instrument cluster service and removal is im­
proved. Refer to Group 21 - Transmission for select­ ing the proper pinion, and selecting and indexing the
proper adapter.

DISTANCE
SENSOR

DISTANCE SENSOR TEST For testing of the distance sensor and related com­
ponents refer to the Vehicle Diagnostics Test Proce­ dure Manual.
DISTANCE SENSOR REMOVAL AND INSTALLATION (1) Remove harness connector from sensor. Be sure
weather seal stays on harness connector. (2) Remove sensor by loosening sensor coupling
nut from the pinion gear adapter until sensor is free (Fig. 5).
(3) To install the sensor, reverse the removal pro­
cedures. Tighten coupling nut to 17 N»m (150 in. lbs.)

•

INSTRUMENT PANEL
AND
GAUGES
8E - 3
MALFUNCTION INDICATOR (CHECK ENGINE)

Fig.
5
Distance Sensor
If
the
input from
one of the
following sensors fails
an internal Powertrain Control Module
(PCM)
self
check,
the PCM
turns
on the
Check Engine Lamp. The
PCM
then substitutes
a
modified signal
in
place
of
the one
that failed until
a
repair
is
made:
• Manifold Absolute Pressure (MAP) Sensor
• Throttle Position Sensor
• Coolant Temperature Sensor
• Battery Voltage Sense
• Battery Voltage
Too
High
Refer
to the
appropriate Powertrain Diagnostic
Test Procedures manual
for
further information.

ELECTRONIC DIGITAL CLOCK
The electronic digital clock
is in the
radio.
The

clock
and
radio each
use the
display panel built into
the radio.
A
digital readout indicates
the
time
in

hours
and
minutes whenever
the
ignition switch
is in

the
ON or ACC
position. When
the
ignition switch
is in the OFF
position
or

when
the
radio frequency
is
being displayed, time keeping
is
accurately maintained. The procedure
for
setting
the
clock varies slightly
with each radio.
The
correct procedure
is
described under
the
individual radio operating instructions
re­

ferred
to in the
Owner Manual supplied with
the ve­

hicle.

MESSAGE CENTER—GAS ENGINE

The message center
(Fig. 6),
located above
the

Heater-A/C controls, includes warning lamps
for the:

• brake systems (parking
and
service)
•
ABS
brakes • liftgate open (Ramcharger only)
• maintenance required.

O/D
BRAKE
(P)(7

GATE OPEN

MAINT
REQD.

J938E-54
Fig.
6
Message Center—Gas Engine

EMISSIONS
MAINTENANCE REMINDER
This system
is
designed
to act as a
reminder that
scheduled vehicle emissions maintenance should
be

performed.
It is not
intended
to
indicate
a
warn­
ing
or
that
a
state
of
emergency exists which must
be
corrected
to
insure safe vehicle opera­
tion.
The
components covered
by the
system include
the
EGR
system,
PCV
valve,
and
oxygen sensor. Refer
to
Group
25 -
Emissions,
for
further informa­
tion.

ABS
WARNING
LIGHT
This light monitors
the ABS
Brake System. This
light will come
on
when
the
ignition
key is
turned
to

the
ON
position
and may
stay
on for as
long
as

thirty seconds.
If the ABS
light remains
on or
comes on during driving,
it
indicates that
the ABS
portion
of
the
brake system
is not
functioning. Refer
to
Group
5 -
Brakes
for
further information.

BRAKE
SYSTEM WARNING
LIGHT
The dual brake system provides
a
reserve braking
capability
in the
event
of a
failure
to a
portion
of the

hydraulic system. Failure
of
either
of the
dual sys­
tem
is
indicated
by the
brake warning light which
will glow when
the
service brake pedal
is
depressed.
The light will remain
on
until
the
cause
is
corrected. The light will also come
on
when
the
parking
brake
is
applied with
the
ignition
in the ON
position.
Refer
to
Group
5 -
Brakes
for
further information.

8E
- 4
INSTRUMENT PANEL
AND
GAUGES

•
MESSAGE CENTER—DIESEL
ENGINE

The message center (Fig. 7), which
is
located above
the Heater-A/C controls, includes warning lamps
for

the:

• brake systems (parking
and
service brakes)
• ABS brakes
• water
in
fuel
• wait
to
start (controlled
by Air
Heater Control
Module)
• Low Fuel.

BRAKE

CUMMINS
TURBO
DIESEL,

LOW
FUEL

DIESEL
FUEL ONLY WATER
IN
FUEL
WAIT
TO
START
J938E-55

Fig.
7
Message Center—Diesel Engine

ABS
WARNING LIGHT
This light monitors
the
ABS Brake System. This
light will come
on
when the ignition key
is
turned
to

the
ON
position
and may
stay
on for as
long
as

thirty seconds.
If
the ABS light remains
on or
comes
on during driving,
it
indicates that
the
ABS portion
of
the
brake system
is not
functioning. Refer
to
Group
5 -
Brakes
for
further information.
BRAKE
SYSTEM WARNING LIGHT

The Brake light
is
connected
to a
sensor that mon­
itors vacuum
in
the brake booster system. The Brake
light when
lit
indicates LOW VACUUM. The dual brake system provides
a
reserve braking
capability
in
the event
of a
failure
to a
portion
of
the
hydraulic system. Failure
of
either
of the
dual sys­
tem
is
indicated
by the
brake warning light which
will glow when
the
service brake pedal
is
depressed.
The light will remain
on
until
the
cause
is
corrected. The light will also come
on
when
the
parking
brake
is
applied with the ignition
in
the ON position. Refer
to
Group
5 -
Brakes
for
further information.

WATER
IN
FUEL
The Water
In
Fuel light
is
connected
to a
sensor lo­
cated
in the
fuel filter.
If
water collects
in the
fuel/
water separator filter,
the
Water
In
Fuel indicator
will light.

WAIT
TO
START
The Wait
To
Start light
is
connected
to a
sensor
that monitors intake
air
temperature
in the
intake
manifold.
If
intake
air
temperature
is low and
igni­
tion switch
is in
ON position,
the
PCM sends current
to
the
intake manifold
air
heaters
and the
Wait
To
Start light. This intake manifold preheat cycle
is

controlled
by an
electronic
Air
Heater Control Mod­

ule.
LOW FUEL
The Low Fuel light
is
connected
to a
sensor
in the

fuel tank. When the fuel level reaches approximately 1/6
of a
tank,
the
words LOW FUEL will illuminate
and remain
on
until fuel
is
added.

•

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

•

INSTRUMENT
PANEL
AND
GAUGES
8E - 7

STEERING PUMP
ENGINE
BLOCK
J9U9-74

Fig.
4 Oil
Pressure
Sending
Unit—Diesel
Engine
COMBINATION
OIL
UNIT
TEST
(FIG. 5)
The combination oil unit has 2 functions:
(1) The normal closed circuit keeps the oil pressure
warning lamp on until there is oil pressure. (2) The sending provides a resistance that varies
with oil pressure.
To test the normally closed oil lamp switch, discon­
nect the locking connector and measure the resis­
tance between the switch terminal and the metal
housing. The ohmmeter should read 0 ohms. Start
the engine.
If there is oil pressure, the ohmmeter should read
an open circuit. To test the sending unit, measure the resistance
between the sending unit terminal and the metal
housing. The ohmmeter should read open, Start the engine.
The ohmmeter should read between 30 to 55 ohms,
depending on engine speed, oil temperature, and oil
viscosity.
If the previous results are not obtained, replace the
switch.

SEAT
BELT
WARNING
SYSTEM
For testing of this system refer to Section 8M -
Seat Belt Warning Systems.

BRAKE
SYSTEM
WARNING
LAMP
(FIG. 6) The brake warning lamp illuminates when the
parking brake is applied with the ignition key
turned ON. The same lamp will also illuminate should one of the two service brake systems fail
when the brake pedal is applied. To test the system
turn the ignition key ON, and apply the parking
brake. If the lamp fails to light, inspect for a burned
out bulb, disconnected socket, a broken or discon-
ENGINE WARNING LAMP DIAGNOSIS
OIL PRESSURE
FUNCTION

TURN

IGNITION

SWITCH
"OH"
(DO NOT
ISTART ENGINE)! LAMP "OFF'
LAMP "ON"
DEFECTIVE BULB START AND IDLE
ENGINE
BULB SOCKET OR WIRING OPEN LAMP STAYS
"ON" TURN OFF
ENGINE LAMP GOES
"OFF" DEFECTIVE
SWITCH CHECK FOR
GROUNDED WIRING
WARNING
LIGHT
OK CHECK FOR
LOW OIL LEVEL
ENGINE OIL
PRISSURi
LOW
REFER TO
ENGINE SERVICE DIAGNOSIS ENGIM

PRES
0
IE OIL
1

SURE
1
,K I

DEFECTIVE SWITCH TEST ENGINE
OIL PRESSURE

PR1448C

SWITCH
(LIGHT)
SENDING
UNIT

(GAUGE)

898E-2

Fig.
5 Combination Oil Unit Terminals
nected wire at the switch. The lamp also lights when
the ignition switch is turned to the START position. To test the service brake warning system,
(1) Raise the vehicle on a hoist.
(2) Open a wheel cylinder bleeder while a helper

8E
- 8 INSTRUMENT PANEL AND GAUGES

•

BRAKE

WARNING
LAMP
SWITCH TO BRAKE
WARNING LAMP

PR!
451

Fig.
6
Brake Warning
Lamp
Switch
depresses
the
brake pedal
and
observes
the
warning

lamp.

If
the
lamp fails
to
light, inspect
for:

•
a
burned
out
bulb
• disconnected socket
•
a
broken
or
disconnected wire
at the
switch. If
the
bulb
is not
burned
out and the
wire continu­
ity
is
proven, replace
the
brake warning switch.
The

switch
is in the
brake line
Tee
fitting mounted
on

the frame rail
in the
engine compartment below
the

master cylinder.

CAUTION:
If
wheel cylinder bleeder
was
opened

check
master cylinder fluid level.

On Diesel Models
The
Brake light
is
also con­
nected
to a
sensor that monitors vacuum
in the

brake booster system.
The
Brake light when
lit
indi­ cates
LOW
VACUUM. Refer
to
Group
5 -
Brakes
for

more information.

TEMPERATURE
GAUGE CIRCUIT TEST
(1) Remove temperature gauge. Refer
to
Gauge
Re­

placement. (2) Check continuity
in the
wire between
the
tem­
perature sensor
and the
temperature gauge (sensor
input
pin)
(Figs.
7, 8 and 9).
(3) With
the
ignition switch
in the ON
position,
check
for
battery voltage across
the B + pin and the

Ground
pin.
(TURN
IGNITION
KEY
"ON"

(DO
NOT
START
ENGINE

I
RELEASE
PARKING
BRAKE)
I

I

[
WARNING
LIGHT
GOES
I
"ON"
I

1
(LIGHT
SHOULD
BE
"OFF")!
X

APPLY PARKING BRAKE (WARNING
LIGHT

SHOULD
GO "ON")

BRAKE
SYSTEM
LEAKING FLUID
X

WARNING
LIGHT

FAILS
TO GO "ON" GROUNDED WIRING
BULB
BURNED
OUT

SHORTED PARKING BRAKE
OR BRAKE WARNING SWITCH

X
DISCONNECTED
OR
FAULTY

BULB
SOCKET
FAULTY BRAKE SYSTEM PROPORTIONING VALVE
UNIT*
BROKEN
WIRE
OR
WIRE
DISCONNECTED
AT
PARKING
BRAKE
SWITCH

X

FAULTY PARKING
BRAKE
SWITCH

X

APPLY SERVICE BRAKES
(WARNING
LIGHT

SHOULD
NOT GO "ON")

JZ
X

TEST SERVICE BRAKE WARNING
SYSTEM FUNCTION*

X
WARNING
LIGHT
GOES

"ON"

WARNING
LIGHT

DOES
NOT GO "ON"
BRAKE
SYSTEM
LEAKING FLUID
OPEN CIRCUIT
IN
WIRING
TO SERVICE BRAKE SWITCH
X

GROUNDED WIRING
OR

SHORTED BRAKE WARNING SWITCH

LOOSE
BULKHEAD CONNECTOR
X

FAULTY BRAKE SYSTEM
PROPORTIONING VALVE
UNIT*

FAULTY SERVICE BRAKE SWITCH

X
•TESTS
ARE
DESCRIBED
IN APPROPRIATE
SECTION
OF
SERVICE MANUAL
FAULTY SERVICE BRAKE
SYSTEM PROPORTIONING VALVE
UNIT*
PR1449A

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
- 12
INSTRUMENT PANEL
AND
GAUGES

•
CLUSTER AND GAUGE
SERVICE
PROCEDURES

INDEX
page
Cluster Bezel
12

Cluster
Mask
and
Lens
12
Fuel Gauge
13

Instrument
Cluster Assembly
12

Lamp Bulb Replacement—Message Center
..... 15

CLUSTER
BEZEL
REMOVAL
(1) Disconnect negative cable from battery.
(2) Tape
or
cover steering column
to
prevent dam­
age
to
paint.
(3) Remove
2
screws and remove map lamp.

CAUTION:
Map
lamp must
be
removed
to
prevent

damage
to
instrument panel.

(4) Remove
6
screws which attach cluster bezel
to

base panel (Fig.
1).
Make sure
the
screw below
the
Heater-A/C control
is
removed.
(5)
Place column shift lever
in
Position
"1".

(6) Remove bezel
by
pulling
top
edge rearward
to

clear brow. Disengage attaching clips around bottom
of bezel
and
complete removal
of
bezel.
(7)
If
bezel
is
equipped with
a
four wheel drive
in­

dicator, remove bulb socket
as
bezel
is
removed.
(8) Disconnect message center wires.

INSTRUMENT
CLUSTER BEZEL
J938E-51
Fig.
1 instrument
Cluster
Bezel

INSTALLATION
(1) Connect bulb socket
for
four wheel drive indi­
cator
if
equipped.

(2)
Connect message center wires.
(3) Engage attaching clips around bottom
of
bezel,
roll bezel into position.
(4) Install
6
mounting screws. page

Lamp Bulbs
. . 15
Printed
Circuit
Board
13

PRND21
Indicator
. 15

Specifications
15

Speedometer/Odometer
14

(5)
Install map lamp.
(6) Remove tape from steering column.
(7) Connect negative cable
to
battery.

CLUSTER
MASK AND LENS REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove cluster bezel.
(3) Remove
8
screws holding mask
and
lens.
(4) Remove mask
and
lens.

INSTALLATION
(1) Position mask
and
lens.
(2) Install
8
screws.
(3) Install cluster bezel.
(4) Connect negative cable
to
battery.

INSTRUMENT CLUSTER ASSEMBLY
(Fig.
2)

REMOVAL
(1) Disconnect negative cable from battery.
(2) Tape
or
cover steering column
to
prevent dam­
age
to
paint.
(3) Remove bezel.
(4) Remove lower steering column cover
4
screws.

(5)
Spread upper steering column cover
out of
the
locking tangs
and
slide downward. (6) Disconnect PRND21 actuator cable from steer­
ing column
if
equipped.
(7) Loosen heater
and
A/C control. Pull rearward
to clear forward mount
on
cluster housing.
(8) Remove
6
screws that retain cluster. Pull clus­
ter rearward
and
disconnect
2
large connectors.
(9) Remove cluster.

INSTALLATION
(1) Connect
2
large connectors
to
cluster.
(2) Position cluster
to
instrument panel and install
6 retaining screws.
(3) Install heater A/C control.
(4) Connect PRND21 actuator
to
steering column
if

equipped.

(5)
Position upper steering column cover
and
slide
upward until tangs snap into place.

8E - 16 INSTRUMENT PANEL AND GAUGES
• SWITCH AND
PANEL
COMPONENT
SERVICE

INDEX

page

Ash
Tray
20
Cigar
Lighter
........................ 20
Four
Wheel Drive
Indicator
19

Fuse
Block
and
Flashers
................... 19

Glove
Box 21

Heater A/C Control
17
page

Heater Control
16

Hood
Release
19
Illumination
Bulb Replacement
22

Message
Center Module
................... 18

Steering Column Lowering
and
Raising
16
Switches
17
DISCONNECT NEGATIVE CABLE FEOM
BATTERY IN ENGINE COMPAETMENT BE­ FORE SERVICING INSTRUMENT PANEL.
STEERING COLUMN LOWERING AND RAISING When servicing the instrument panel and the Low­
ering and Raising of the steering column is required,
the following is the procedure for doing so: This procedure is not for removing and replac­
ing the steering column. Refer to Group - 19 Steering of this manual for the removal and re­
placement procedures.

LOWERING STEERING COLUMN
(1) Disconnect negative cable from battery.

(2)
Remove 3 toe plate nuts and washers (Fig. 1).
(3) Remove 1 toe plate screw.
(4) Remove 4 screws attaching lower steering col­
umn cover and remove cover. The fuse block is at­
tached to this cover and should be supported when cover is removed.
(5) Spread upper steering column cover out of lock­
ing tangs and slide downward.
(6)
Disconnect cable from shift indicator bracket.

(7)
Remove 2 nuts and washers attaching steering
column bracket to instrument panel steering column support bracket.
(8)
Allow column to lower and rest on seat.
STEERING

COLUMN SUPPORT

WASHER
AND NUT

Fig.
1 Steering
Column
Mounting
RAISING STEERING COLUMN

(1) Raise steering column assembly against the in­
strument panel support bracket. (2) Install 2 steering column bracket washers and
nuts (Finger Tighten Only).

CAUTION:
Check that
all
wiring
is
clear
and not
pinched.

(3) Tighten the 2 bracket nuts to 12 Nnn-(110 in.
lbs.) torque. (4) Slide toe plate into position, install attaching
screw, tighten to 4 N®m (35 in. lbs.).
(5) Install toe plate nuts and washers and tighten
to 23 N*m (200 in. lbs.).
(6)
Connect cable to shift indicator bracket.

(7)
Position upper steering column cover and slide
upward until tangs snap into place.
(8) Install fuse block to cover.

(9)
Position lower steering column cover and in­
stall 4 attaching screws.
HEATER CONTROL

REMOVAL
(1) Remove map lamp.
(2) Remove cluster bezel (refer to Cluster Bezel Re­
moval). (3) Remove 2 control attaching screws. (4) Pull control rearward.
(5) Disconnect illumination lamp, and wire connec­

tions.
(6)
Disconnect control cables.

(7)
Remove control.

INSTALLATION
(1) Position control near panel.
(2) Connect control cables to control (see Heater
A/C Section). (3) Connect illumination lamp, and wire connec­

tors.

(4) Push control into panel.
(5) Install 2 control mounting screws.

(6)
Install bezel.

(7)
Install map lamp.

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