1993 DODGE TRUCK transmission oil

•

COOLING SYSTEM
7 - 15
SERVICE
PROCEDURES

INDEX
page
Coolant
26
Coolant Reserve/Overflow System
30

Cooling System Cleaning/Reverse Flushing
28

Cooling System Fan—Diesel Engine
. 37

Cooling System
Fan—Gas
Engines
36

Cooling System
Hoses
34
Draining Cooling System
27

Pressure
Testing
Radiator
Caps
............. 32

Radiator Pressure
Cap 31

Radiators
32

Refilling
the
Cooling System
28

WATER PUMPS—EXCEPT DIESEL
A centrifugal water pump circulates coolant
through the water jackets, passages, intake manifold,
radiator core, cooling system hoses and heater core.
The pump is driven from the engine crankshaft by a drive belt. The water pump impeller is pressed onto the rear
of a shaft that rotates in a bearing pressed into the
water pump body. The body has a small hole for ven­
tilation. The water pump seals are lubricated by an­
tifreeze in the coolant mixture. Additional lubrication is not necessary. A quick test to determine if pump is working is to
check if heater warms properly. A defective water
pump will not be able to circulate heated coolant
through the long heater hose to the heater core. The water pump on all models can be removed
without discharging the air conditioning system (if equipped).
REMOVAL The water pump on all gas powered engines is
bolted directly to the engine timing chain case/cover.
A gasket is used as a seal between the water pump
and timing chain case/cover.
If water pump is replaced because of bearing/shaft
damage or leaking shaft seal, the mechanical cooling
fan assembly should also be inspected. Inspect for fa­ tigue cracks, loose blades or loose rivets that could
have resulted from excessive vibration. Replace fan if any of these conditions are found. Also check condi­
tion of the thermal viscous fan drive. Refer to Vis­
cous Fan Drive in this group. (1) Disconnect negative battery cable from battery.
(2) Drain cooling system. Refer to Draining Cool­
ing System in this group. Do not waste reusable coolant. If solution is clean,
drain coolant into a clean container for reuse.
(3)
Disconnect throttle cable from clip at top of fan
shroud.
page

Testing
Cooling System
for
Leaks
. 29

Thermostat
22

Transmission
Oil
Cooler—Diesel
35

Transmission
Oil
Cooler—Except Diesel
35

Transmission Oil-To-Air Cooler
36
Viscous
Fan
Drive
38

Water
Pump
Bypass
Hose—All
Gas
Powered
Engines
.............................. 19

Water
Pumps—5.9L Diesel
18

Water
Pumps—Except Diesel
15
(4) Unsnap coolant reserve/overflow tank (up and
out) from the T-slots on side of fan shroud (Fig. 1) and lay aside. Do not disconnect hose or drain cool­
ant from tank.
(5) Remove the fan shroud from the radiator. Do
not remove shroud from vehicle at this time.
FAN

SHROUD
J9107-67

Fig.
1 Fan
Shroud—Except
Diesel

(6) Remove upper radiator hose at radiator. Special
Clamp Tool number 6094 (Fig. 2) may be used to re­
move the constant tension clamps.
(7) The thermal viscous fan drive is attached
(threaded) to the water pump hub shaft (Fig. 3). Re­
move the fan/fan drive assembly from water pump by
turning the mounting nut counterclockwise (as viewed from front). Threads on the fan drive are RIGHT HAND. A Snap-On 36 MM Fan Wrench (number SP346 from Snap-On Cummins Diesel Tool
Set number 2017DSP) can be used. Place a bar or
screwdriver between the water pump pulley bolts (Fig. 3) to prevent the pulley from rotating.
If water pump is being replaced, do not unbolt fan
blade assembly (Fig. 3) from the thermal control fan drive.

7 - 30
COOLING
SYSTEM

•

COOLING
SYSTEM

Fig.
39
Pressure
Testing
Cooling
System—Typical bulges while testing, replace as necessary. Observe
gauge pointer and determine condition of cooling sys­
tem according to following criteria:
Holds Steady: If pointer remains steady for two
minutes, serious coolant leaks are not present in sys­
tem. However, there could be an internal leak that does not appear with normal system test pressure. If
it is certain that coolant is being lost and leaks can­
not be detected, inspect for interior leakage or per­
form Internal Leakage Test.
Drops Slowly: Indicates a small leak or seepage is
occurring. Examine all connections for seepage or
slight leakage with a flashlight. Inspect radiator,

hoses,
gasket edges and heater. Seal small leak holes
with a Sealer Lubricant (or equivalent). Repair leak
holes and inspect system again with pressure ap­
plied.
Drops Quickly: Indicates that serious leakage is
occurring. Examine system for external leakage. If
leaks are not visible, inspect for internal leakage.
Large radiator leak holes should be repaired by a
reputable radiator repair shop.
INTERNAL LEAKAGE INSPECTION Remove engine oil pan drain plug and drain a
small amount of engine oil. If coolant is present in
the pan, it will drain first because it is heavier than
oil.
An alternative method is to operate engine for a
short period to churn the oil. After this is done, re­
move engine dipstick and inspect for water globules.
Also inspect transmission dipstick for water globules and transmission fluid cooler for leakage.

WARNING:
WITH
PRESSURE TESTER TOOL
7700
INSTALLED
ON
RADIATOR,
DO
NOT ALLOW
PRES­

SURE
TO
EXCEED
110 KPA (20
PSI). PRESSURE

WILL
BUILD
UP
QUICKLY
IF A
COMBUSTION LEAK

IS
PRESENT.
TO
RELEASE
PRESSURE,
ROCK

TESTER
FROM SIDE
TO
SIDE. WHEN REMOVING

TESTER,
DO NOT
TURN TESTER MORE THAN
1/2

TURN
IF
SYSTEM
IS
UNDER
PRESSURE.
Operate engine without pressure cap on radiator
until thermostat opens. Attach a Pressure Tester to
filler neck. If pressure builds up quickly it indicates a combustion leak exists. This is usually the result of
a cylinder head gasket leak or crack in engine. Re­
pair as necessary.
If there is not an immediate pressure increase,
pump the Pressure Tester. Do this until indicated
pressure is within system range of 110 kPa (16 psi). Fluctuation of gauge pointer indicates compression or
combustion leakage into cooling system.
Because the vehicle is equipped with a catalytic
converter, do not remove spark plug cables or short
out cylinders (non-diesel engines) to isolate compres­
sion leak.
If the needle on dial of pressure tester does not
fluctuate, race engine a few times to check for an ab­ normal amount of coolant or steam. This would be
emitting from exhaust pipe. Coolant or steam from
exhaust pipe may indicate a faulty cylinder head
gasket, cracked engine cylinder block or cylinder
head. A convenient check for exhaust gas leakage into
cooling system is provided by a commercially avail­ able Block Leak Check tool. Follow manufacturers
instructions when using this product.
COMBUSTION LEAKAGE TEST-WITHOUT
PRESSURE TESTER DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean container for reuse.

WARNING:
DO NOT
REMOVE CYLINDER BLOCK DRAIN PLUGS
OR
LOOSEN RADIATOR DRAIN-

COCK
WITH
SYSTEM
HOT AND
UNDER PRES­

SURE.
SERIOUS BURNS FROM COOLANT
CAN

OCCUR.

Drain sufficient coolant to allow thermostat re­
moval. Refer to Thermostat Replacement. Disconnect
water pump drive belt. Add coolant to radiator to bring level to within 6.3
mm (1/4 in) of top of thermostat housing.

CAUTION:
Avoid
overheating.
Do not
operate
en­

gine
for an
excessive
period
of
time.
Open
drain-

cock
immediately
after
test
to
eliminate
boil
over.

Start engine and accelerate rapidly three times, to
approximately 3000 rpm while observing coolant. If
internal engine combustion gases% are leaking into
cooling system, bubbles will appear in coolant. If
bubbles do not appear, internal combustion gas leak­ age is not present.

COOLANT
RESERVE/0WERFL0W
SYSTEM
The coolant reserve/overflow system (Fig. 40 or 41)
works in conjunction with the radiator pressure cap.

•

COOLING
SYSTEM
7 - 33 The radiator supplies sufficient heat transfer to
cool the engine and automatic transmission (if equipped).

RADIATOR COOLANT FLOW CHECK
Use the following procedure to determine if coolant
is flowing through the cooling system.
(1) Idle engine until operating temperature is
reached. If the upper radiator hose is warm to the
touch, the thermostat is opening and coolant is flow­ ing to the radiator.

WARNING:
HOT,
PRESSURIZED COOLANT
CAN
CAUSE
INJURY
BY
SCALDING. USING
A
RAG
TO

COVER
THE
RADIATOR
PRESSURE
CAP,
OPEN RADIATOR
CAP
SLOWLY
TO THE
FIRST STOP.
THIS
WILL
ALLOW
ANY
BUILT-UP
PRESSURE
TO
VENT
TO
THE
RESERVE/OVERFLOW TANK. AFTER
PRESSURE
BUILD-UP
HAS
BEEN RELEASED,
RE­

MOVE
CAP
FROM FILLER NECK.

(2) Drain a small amount of coolant from the radi­
ator until the ends of the radiator tubes are visible
through the filler neck. Idle the engine at normal op­
erating temperature. If coolant is flowing past the
exposed tubes, the coolant is circulating.

RADIATOR REMOVAL-EXCEPT DIESEL
(1) Disconnect negative battery cable from battery.

WARNING;
DO NOT
REMOVE
THE
CYLINDER BLOCK DRAIN PLUGS
OR
LOOSEN
THE
RADIATOR
DRAINCOCK
WITH
THE
SYSTEM
HOT AND
UNDER
PRESSURE.
SERIOUS BURNS FROM COOLANT
CAN OCCUR.

(2) Drain the cooling system. Refer to Draining
Cooling System.
(3) Disconnect throttle cable from clip at radiator
fan shroud. (4) Remove hose clamps and hoses from radiator.
Special Clamp Tool number 6094 (Fig. 44) may be
used to remove the constant tension clamps.
(5) Remove coolant reserve/overflow tank hose
from radiator filler neck nipple.
(6) If equipped with an automatic transmission
(except diesel), disconnect oil cooler hoses at radiator
lower tank.
(7) Remove fan shroud mounting bolts/clips and
position shroud rearward on engine (Fig. 45). (8) Loosen radiator lower mounting bolts. Remove
the upper mounting bolts. Lift radiator straight up and out of engine compartment. Take care not to
damage radiator cooling fins or tubes.

INSTALLATION
(1) Position shroud rearward on engine.
(2) Slide radiator into position. Place behind radi­
ator support with lower mounting holes (slots) rest-
HOSE
CLAMP
TOOL
6094
HOSE

CLAMP

J9207-36

Fig.
44
Hose
Clamp
Tool
RADIATOR SHROUD
MOUNTING MOUNTING
BOLTS
CUPS
RADIATOR
V1

FAN SHROUD^
J9207-44
Fig.
45 Radiator and Fan
Shroud—Gas Engines

ing on loosened bottom mounting bolts. Install upper
mounting bolts. Tighten all mounting bolts to 11
N*m (95 in. lbs.) torque.
(3) Connect radiator hoses.
(4) Connect transmission oil cooler lines to bottom
tank. Tighten hose clamps to 4 N#m (35 in. lbs.)
torque.
(5) Position fan shroud on radiator flange. Install
mounting clips (Fig. 45).
(6) Connect throttle cable to fan shroud.
(7) Position heater controls to full heat position.
(8) Fill cooling system with coolant. Refer to Refill­
ing Cooling System in this group.
(9) Operate engine until it reaches normal temper­
ature. Check cooling system and automatic transmis­
sion (if equipped) fluid levels.

RADIATOR REMOVAL-DIESEL
(1) Disconnect negative battery cable from battery.

•

COOLING
SYSTEM
7 - 35

HOSE
CLAMP TOOL
6094
HOSE

CLAMP

J9207-36
Fig.
48
Hose
damp Tool

TRANSMISSION
OIL
COOLER—EXCEPT DIESEL
The automatic transmission oil is cooled when it
passes through a cooler in the radiator lower tank (Fig. 49 and 50).

h*-TRANSMISSION

- OIL
COOLER

FRONT
OF
VEHICLE
AUTOMATIC

TRANSMISSION
PRESSURE
LINE
6 AND
8
CYLINDER ENGINE

RETURN
LINE
RY402

Fig.
49 Top View of
Transmission
Oil
Cooling
Circuit—Except Diesel—Typical

COOLING
TUBE (CUT-A-WAY)

DRAIN
COCK
HOSE

CLAMP
HOSE
TO

COOLER
LINE
HOSE
TO

COOLER
LINE

RY401

Fig.
50 Automatic
Transmission
Oil Cooler—Except
Diesel—
Typical

In case of a leak in the transmission oil cooler, en­
gine coolant may become mixed with transmission
fluid or transmission fluid may enter engine cooling system. Both cooling system and transmission should
be drained and inspected in the event cooler is leak­ ing.
REPLACING
OIL
COOLER
IN
BOTTOM
TANK

Remove radiator. Refer to Radiator removal in this
group. The servicing should be performed by a qual­
ified repair facility.
Once the repaired or replacement radiator has been
installed, fill the cooling system and inspect for

leaks.
Refer to Refilling Cooling System and Testing Cooling System For Leaks sections in this group. If
the transmission operates properly after repairing
the leak, drain the transmission and remove the
transmission oil pan. Inspect for sludge and/or rust. Inspect for a dirty or plugged inlet filter. If none of
these conditions are found, the transmission and
torque convertor may not require reconditioning. Re­
fer to Group 21 for automatic transmission servicing.

1RANSMISSI0N
OIL
COOLER-DIESEL
The transmission oil cooler is mounted to a bracket
on the turbocharger side of the engine (Fig. 51).

TRANSMISSION
OIL
COOLER
Fig.
51 Automatic
Transmission
Oil Cooler—5.9L

Diesel
REMOVAL

In case of a leak in the transmission oil cooler, en­
gine coolant may become mixed with transmission
fluid or transmission fluid may enter engine cooling system. Both cooling system and transmission should
be drained and inspected in the event cooler is leak­ ing. (1) Disconnect negative battery cable at battery.
(2) Drain cooling system. Refer to Draining Cool­
ing System. (3) Disconnect coolant lines from cooler.
(4) Disconnect transmission oil lines from cooler.
Plug cooler lines to prevent oil leakage. (5) Remove oil cooler mounting straps.
(6) Lift oil cooler off of mounting bracket.

INSTALLATION
(1) Position oil cooler on bracket.
(2) Install mounting straps.
(3) Connect transmission oil lines to cooler.

7 - 36
COOLING
SYSTEM

• (4) Connect coolant hoses to cooler.

(5)
Connect battery cable to battery.

(6)
Fill cooling system. Refer to Refilling Cooling
System in this section. (7) Check transmission oil level and fill as neces­
sary.

TRANSMISSION
OIL/TO-AIR
COOLER
Oil to air transmission coolers are mounted ahead
of the radiator and operate in conjunction with the
main cooler (Figs, 52 or 53). The transmission oil is
routed through the main cooler first, then the auxil­ iary cooler, before returning to the transmission.
FRONT
OIL-TO-AIR
COOLER

RADIATOR
RADIATOR GRILL SUPPORT RETURN JO

_
TRANSMISSION

*
PRESSURE

(FROM BOTTOM COOLER)
VIEW
IN
CIRCLE J9007-75 Fig.
52
Transmission
Oil-to-Air Cooler—Except

Diesel—
Typical

AUXILIARY
OIL TO AIR
COOLER
J9107-73
Fig.
53
Transmission
Oil-to-Air
Cooler—Diesel

Engine—Typical
COOLING
SYSTEM FAN—GAS ENGINES

Also refer to Viscous Fan Drive in this group for
additional information.
REMOVAL (1) Disconnect negative battery cable from battery.
(2) Remove throttle cable at top of fan shroud.
(3) Unsnap coolant reserve/overflow tank from fan
shroud and lay aside. The tank is held to shroud
with T-shaped slots. Do not disconnect hose or drain
coolant from tank.
(4) The thermal Viscous Fan Drive/Fan Blade As­
sembly is attached (threaded) to water pump hub
shaft (Fig. 54). Remove fan blade/viscous fan drive
assembly from water pump by turning mounting nut
counterclockwise as viewed from front. Threads on
viscous fan drive are RIGHT HAND. A Snap-On 36
MM Fan Wrench (number SP346 from Snap-On Cummins Diesel Tool Set number 2017DSP) can be
used. Place a bar or screwdriver between water pump
pulley bolts (Fig. 54) to prevent pulley from rotating. Do not attempt to remove fan/viscous fan drive as­
sembly from vehicle at this time.
FAN BLADE

ASSEMBLY

THREADED NUT WATER
PUMP

PULLEY
PULLEY
BOLTS
WATER PUMP
THREADED SHAFT
(WATER PUMP HUB)
VISCOUS
FAN DRIVE CRANKSHAFT
PULLEY
J9307-32

Fig.
54 Fan
Blade/Viscous
Fan
Drive—Gas
Engines
Do not unbolt fan blade assembly (Fig. 54) from
viscous fan drive at this time.
(5) Remove fan shroud attaching hardware (two
bolts at bottom-two clips at top). (6) Remove fan shroud and fan blade/viscous fan
drive assembly as a complete unit from vehicle.
After removing fan blade/viscous fan drive assem­
bly, do not place viscous fan drive in horizontal po­ sition. If stored horizontally, silicone fluid in the
viscous fan drive could drain into its bearing assem­
bly and contaminate lubricant.

•

ELECTRICAL
8A - 9
ENGINE STARTER MOTOR TEST PROCEDURES
GENERAL INFORMATION
The starting system consists of an:
• ignition switch
• starter relay
• park/neutral position switch (automatic transmis­ sion)
• clutch switch (diesel engine-manual transmission)
• wiring harness
• battery
• starter motor with an integral solenoid. These components form 2 separate circuits. A high
amperage circuit that feeds the starter motor up to
300+ amps-gas engine; 500+ amps-diesel engine,
and a control circuit that operates on less than 20
amps (Fig. 1).
a.
BATTERY +
1
IGNITION
SWITCH 1 AUTOMATIC TRANSMISSION
•
J
NEUTRAL SAFETY SWITCH
I 4-
"JL"
MOTOR
m, ...
STA3-TERSOLENO,Dnlh
STARTER RELAY

1"

898A-14
Fig.
1 Starting
System
Components

STARTER SYSTEM DIAGNOSTIC INSPECTIONS
Before removing any unit from the starter motor
system for repair, perform the following inspections:

BATTERY
INSPECTION
To determine condition of the battery, perform the
testing procedure outlined in the Battery Section.

WIRING INSPECTION
Inspect wiring for damage. Inspect all connections
at the starter motor solenoid, park/neutral position
switch (if equipped), back-up lamp switch connector,
ignition/start switch, and battery (including all
ground connections). Clean and tighten all connec­
tions as required.

SOLENOID, RELAY
AND
IGNITION/START

SWITCH
INSPECTION
Inspect the solenoid, relay and switch to determine
their condition. Also, if equipped with automatic
transmission, inspect condition of the park/neutral position switch. Testing information can be found in
the following pages.
If the following components are working properly
remove the starter motor and follow procedures in
the Testing Section. • battery wiring
switch
solenoid
relay
park/neutral position switch

COLD CRANKING TEST
(1) Battery must first pass load and voltage drop
tests and be fully charged before proceeding. Refer to Battery Test Procedures. (2) Connect a suitable volt-ampere tester to the
battery terminals (Fig. 2). Refer to the operating in­ structions provided with the tester being used.
POSITIVE
CLAMP

898A-15
NEGATIVE
CLAMP
INDUCTION
AMPMETER
CLAMP
Fig.
2
Volt-Amps
Tester
Connections
(Typical)

(3) Fully engage parking brake, place manual
transmission in NEUTRAL, automatic transmission
in PARK. (4) Verify that all lights and accessories are OFF. (5) Remove coil secondary cable from distributor
and connect to ground.
(6) Rotate and hold the ignition switch (key) in the
START position. Note cranking voltage and amper­
age.
(a) If voltage reads above 9.6 volts and amperage
draw reads above (220 amps gas engine) (550 amps
diesel) go to Starter Feed Circuit Tests. (b) If voltage reads 12.5 volts or greater and am-
perate reads 0 to 10 amps, go to Starter Control Circuit Tests.
A cold engine will increase starter motor cur­
rent.

STARTER
FEED
CIRCUIT TESTS
-
(W0LTAGE
DROP
METHOD)
The voltage drop tests will determine if there is ex­
cessive resistance in the high current circuit. When
performing these tests, it is important that the volt­ meter be connected to the terminals that the cables are connected to instead of to the cables themselves.
For example, when testing between the battery and
solenoid, touch the voltmeter test probes to the bat-

8A
- 10
ELECTRICAL
•
STARTING SYSTEM DIAGNOSIS

TEST CONDITIONS • PLACE GEAR SELECTOR
IN
PARK OR NEUTRAL AND SET PARK BRAKE
OR
EQUIVALENT. • VERIFY BATTERY STATE-OF-CHARGE AND CRANKING CAPACITY, SEE BATTERY SECTION.
• CLEAN BATTERY TOP, POSTS, AND TERMINALS.
• VERIFY ALTERNATOR DRIVE BELT TENSION.
• DISCONNECT AND GROUND COIL CABLE. SYMPTOM
SYMPTOM SYMPTOM SYMPTOM SYMPTOM
STARTER FAILS TO STARTER FAILS TO STARTER ENGAGES, STARTER ENGAGES STARTER DOES NOT

ENGAGE.
NO SOUNDS
ENGAGE
SOLENOID FAILS TO TURN DRIVE CLUTCH

DISENGAGE
AFTER
OR RELAY CLICKS ENGINE. DOME
LIGHT
SPINS
OUT
ENGINE STARTS

DIMS

POSSIBLE
CAUSE
POSSIBLE
CAUSE
POSSIBLE
CAUSE
POSSIBLE
CAUSE
POSSIBLE
CAUSE
STARTER CONTROL
RESISTANCE
TOO
RESISTANCE
TOO DRIVE CLUTCH
FAULTY

IGNITION
SWITCH
CIRCUIT
FAULTY
HIGH
IN
STARTER
HIGH
IN
STARTER

FAULTY

FEED CIRCUIT FEED CIRCUIT

BROKEN
TEETH

IGNITION
SWITCH ON RING GEAR
STARTER RELAY

FAULTY
STARTER CONTROL STARTER ASSEMBLY

FAULTY

CIRCUIT
FAULTY FAULTY

STARTER ASSEMBLY
PARK/NEUTRAL
FAULTY

STARTER ASSEMBLY
POSITION STARTER SOLENOID ENGINE

FAULTY

SWITCH
FAULTY

SEIZED

(AUTO
TRANS.) STARTER

FAULTY
OR STARTER
MISADJUSTED STARTER ASSEMBLY IMPROPERLY

FAULTY
MOUNTED
STARTER RELAY
REFER
TO

FAULTY
APPROPRIATE GROUP
AND SECTION OF THIS
MANUAL FOR PROPER
STARTER ASSEMBLY
SERVICE
AND TEST

FAULTY
PROCEDURES
FOR THE
COMPONENTS INVOLVED

J938A-9
tery post and the solenoid threaded stud. The follow­
ing operation will require a voltmeter, accurate to 1/10 of a volt.
Before performing the tests, assure the following
procedures are accomplished:
•
Disconnect the distributor connector (gas engine).

•
Disconnect both wires on the fuel solenoid (diesel engine) (Fig. 3). Verify that:

•
all lights and accessories are OFF

•
transmission shift selector is in PARK (automatic)
or NEUTRAL (manual)

•
parking brake is applied

•
battery is fully charged (refer to Battery Test Pro­
cedures). (1) Connect positive lead of voltmeter to battery
negative post. Connect negative lead of voltmeter to
battery negative cable clamp (Fig. 4). Rotate and
Fig.
3
Diesel
Engine
Fuel
Solenoid

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.)