tow DODGE RAM 2001 Service Service Manual

Only when sufficient heat is present, will the vis-
cous fan drive engage. This is when the air flowing
through the radiator core causes a reaction to the
bimetallic coil. It then increases fan speed to provide
the necessary additional engine cooling.
Once the engine has cooled, the radiator discharge
temperature will drop. The bimetallic coil again
reacts and the fan speed is reduced to the previous
disengaged speed.
DIAGNOSIS AND TESTINGÐVISCOUS FAN
DRIVE
NOISE
NOTE: It is normal for fan noise to be louder (roar-
ing) when:
²The underhood temperature is above the engage-
ment point for the viscous drive coupling. This may
occur when ambient (outside air temperature) is very
high.
²Engine loads and temperatures are high such as
when towing a trailer.
²Cool silicone fluid within the fan drive unit is
being redistributed back to its normal disengaged
(warm) position. This can occur during the first 15
seconds to one minute after engine start-up on a cold
engine.
LEAKS
Viscous fan drive operation is not affected by small
oil stains near the drive bearing. If leakage appears
excessive, replace the fan drive unit.
VISCOUS DRIVE
If the fan assembly free-wheels without drag (the
fan blades will revolve more than five turns when
spun by hand), replace the fan drive. This spin test
must be performed when the engine is cool.
For the following test, the cooling system must be
in good condition. It also will ensure against exces-
sively high coolant temperature.
WARNING: BE SURE THAT THERE IS ADEQUATE
FAN BLADE CLEARANCE BEFORE DRILLING.
(1) Drill a 3.18-mm (1/8-in) diameter hole in the
top center of the fan shroud.
(2) Obtain a dial thermometer with an 8 inch stem
(or equivalent). It should have a range of -18É-to-
105ÉC (0É-to-220É F). Insert thermometer through the
hole in the shroud. Be sure that there is adequate
clearance from the fan blades.
(3) Connect a tachometer and an engine ignition
timing light. The timing light is to be used as a
strobe light. This step cannot be used on the diesel
engine.
(4) Block the air flow through the radiator. Secure
a sheet of plastic in front of the radiator (or air con-
ditioner condenser). Use tape at the top to secure the
plastic and be sure that the air flow is blocked.
(5) Be sure that the air conditioner (if equipped) is
turned off.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR FAN. DO
NOT WEAR LOOSE CLOTHING.
(6) Start the engine and operate at 2400 rpm.
Within ten minutes the air temperature (indicated on
the dial thermometer) should be up to 88É C (190É F).
Fan driveengagementshould start to occur at/be-
tween:
²3.9L/5.2L/5.9L gas engines Ð 79É C (175É F)
²8.0L engine Ð 88É to 96É C (190É to 205É F)
²5.9L diesel engine Ð 71É to 82É C (160É to 179É
F)Engagement is distinguishable by a definite
increasein fan flow noise (roaring). The timing light
also will indicate an increase in the speed of the fan
(non-diesel only).
(7) When viscous drive engagement is verified,
remove the plastic sheet. Fan drivedisengagement
should start to occur at between 57É to 79É C (135É to
175É F). A definitedecreaseof fan flow noise (roar-
ing) should be noticed. If not, replace the defective
viscous fan drive unit.
Fig. 31 Viscous Fan DriveÐTypical
1 - VISCOUS FAN DRIVE
2 - THERMOSTATIC SPRING
3 - MOUNTING NUT TO WATER PUMP HUB
7 - 58 ENGINEBR/BE
FAN DRIVE VISCOUS CLUTCH - 5.9L DIESEL (Continued)

CAUTION: A number or letter is stamped into the
tongue of constant tension clamps. If replacement
is necessary, use only an original equipment clamp
with a matching number or letter.
(3) Remove hose clamps and hoses from radiator.
(4) Remove coolant reserve/overflow tank hose
from radiator filler neck nipple.
(5) Remove the coolant reserve/overflow tank from
the fan shroud (pull straight up). The tank slips into
T-slots on the fan shroud (Fig. 33).
(6) Disconnect electrical connectors at windshield
washer reservoir tank and remove tank.
(7) Remove the four fan shroud mounting bolts
(Fig. 34). Position shroud rearward over the fan
blades towards engine.
(8) Remove the plastic clips retaining the rubber
shields to the sides of radiator. Position rubber
shields to the side.
(9) Remove the two radiator upper mounting bolts
(Fig. 35).
(10) Lift radiator straight up and out of engine
compartment. The bottom of the radiator is equipped
with two alignment dowels that fit into holes in the
lower radiator support panel (Fig. 35). Rubber bis-
cuits (insulators) are installed to these dowels. Take
care not to damage cooling fins or tubes on the radi-
ator and air conditioning condenser when removing.
CLEANING
Clean radiator fins are necessary for good heat
transfer. The radiator and air conditioning fins
should be cleaned when an accumulation of debris
has occurred. With the engine cold, apply cold water
Fig. 33 Coolant Recovery Bottle
1 - T-SLOTS
2 - ALIGNMENT PIN
3 - FAN SHROUD
4 - COOLANT RESERVE/OVERFLOW TANK
Fig. 34 Fan Shroud MountingÐ3.9L/5.2L/5.9L
Engines
1 - RADIATOR SUPPORT
2 - RADIATOR
3 - BOLTS (4)
4 - FAN SHROUD
Fig. 35 Typical Radiator Mounting
1 - MOUNTING BOLTS
2 - RADIATOR
3 - ALIGNMENT DOWELS (2)
4 - RADIATOR SUPPORT
7 - 60 ENGINEBR/BE
RADIATOR - 3.9L/5.2L/5.9L (Continued)

and compressed air to the back (engine side) of the
radiator to flush the radiator and/or A/C condenser of
debris.
INSPECTION
Inspect the radiator side tanks for cracks, broken
or missing fittings also inspect the joint where the
tanks seam up to the radiator core for signs of leak-
age and/or deteriorating seals.
Inspect radiator core for corroded, bent or missing
cooling fins. Inspect the core for bent or damaged
cooling tubes.
INSTALLATION
(1) Position fan shroud over the fan blades rear-
ward towards engine.
(2) Install rubber insulators to alignment dowels
at lower part of radiator.
(3) Lower the radiator into position while guiding
the two alignment dowels into lower radiator sup-
port. Different alignment holes are provided in the
lower radiator support for each engine application.
(4) Install two upper radiator mounting bolts.
Tighten bolts to 11 N´m (95 in. lbs.) torque.
(5) Position the rubber shields to the sides of radi-
ator. Install the plastic clips retaining the rubber
shields to the sides of radiator.
(6) Connect both radiator hoses and install hose
clamps.
(7) Install windshield washer reservoir tank.
(8) Position fan shroud to flanges on sides of radi-
ator. Install fan shroud mounting bolts (Fig. 34).
Tighten bolts to 6 N´m (50 in. lbs.) torque.
(9) Install coolant reserve/overflow tank hose to
radiator filler neck nipple.
(10) Install coolant reserve/overflow tank to fan
shroud (fits into T-slots on shroud).
(11) Install battery negative cables.
(12) Position heater controls tofull heatposition.
(13) Fill cooling system with coolant (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(14) Operate engine until it reaches normal tem-
perature. Check cooling system fluid levels.
RADIATOR - 8.0L
DESCRIPTION
The radiator is a aluminum cross-flow design with
horizontal tubes through the radiator core and verti-
cal plastic side tanks (Fig. 36).
This radiator contains an internal transmission oil
cooler only on the V-10 gas engine and the 5.9L die-
sel engine combinations.
OPERATION
The radiator supplies sufficient heat transfer using
the cooling fins interlaced between the horizontal
tubes in the radiator core to cool the engine.
DIAGNOSIS AND TESTINGÐRADIATOR
COOLANT FLOW
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 PRES-
SURE BUILD-UP HAS BEEN RELEASED, REMOVE
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
operating temperature. If coolant is flowing past the
exposed tubes, the coolant is circulating.
Fig. 36 Cross Flow RadiatorÐTypical
1 - COOLING TUBES
2 - TANKS
BR/BEENGINE 7 - 61
RADIATOR - 3.9L/5.2L/5.9L (Continued)

REMOVAL
(1) Disconnect battery negative cables.
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 7 - COOL-
ING - STANDARD PROCEDURE).
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094). SNAP-ON CLAMP TOOL (NUMBER HPC-20)
MAY BE USED FOR LARGER CLAMPS. ALWAYS
WEAR SAFETY GLASSES WHEN SERVICING CON-
STANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps. If replacement
is necessary, use only an original equipment clamp
with a matching number or letter.
(3) Remove hose clamps and hoses from radiator.
(4) Remove coolant reserve/overflow tank hose
from radiator filler neck nipple.
(5) The coolant recovery/reservoir does not require
removal. Disconnect the overflow hose from the radi-
ator.
(6) Disconnect electrical connectors at windshield
washer reservoir tank and remove tank.
(7) Remove the four fan shroud mounting bolts
(Fig. 37). Position shroud rearward over the fan
blades towards engine.
(8) Remove the two radiator upper mounting bolts
(Fig. 38).
(9) Lift radiator straight up and out of engine com-
partment. The bottom of the radiator is equipped
with two alignment dowels that fit into holes in the
lower radiator support panel (Fig. 38). Rubber bis-
cuits (insulators) are installed to these dowels. Take
care not to damage cooling fins or tubes on the radi-
ator and air conditioning condenser when removing.
CLEANING
Clean radiator fins are necessary for good heat
transfer. The radiator and air conditioning fins
should be cleaned when an accumulation of debris
has occurred. With the engine cold, apply cold water
and compressed air to the back (engine side) of the
radiator to flush the radiator and/or A/C condenser of
debris.
INSPECTION
Inspect the radiator side tanks for cracks, broken
or missing fittings also inspect the joint where the
tanks seam up to the radiator core for signs of leak-
age and/or deteriorating seals.
Fig. 37 Fan Shroud MountingÐ8.0L Engine
1 - RADIATOR SUPPORT
2 - RADIATOR
3 - BOLTS (4)
4 - FAN SHROUD
Fig. 38 Typical Radiator Mounting
1 - MOUNTING BOLTS
2 - RADIATOR
3 - ALIGNMENT DOWELS (2)
4 - RADIATOR SUPPORT
7 - 62 ENGINEBR/BE
RADIATOR - 8.0L (Continued)

Inspect radiator core for corroded, bent or missing
cooling fins. Inspect the core for bent or damaged
cooling tubes.
INSTALLATION
(1) Position fan shroud over the fan blades rear-
ward towards engine.
(2) Install rubber insulators to alignment dowels
at lower part of radiator.
(3) Lower the radiator into position while guiding
the two alignment dowels into lower radiator sup-
port. Different alignment holes are provided in the
lower radiator support for each engine application.
(4) Install two upper radiator mounting bolts.
Tighten bolts to 11 N´m (95 in. lbs.) torque.
(5) Connect both radiator hoses and install hose
clamps.
(6) Install windshield washer reservoir tank.
(7) Position fan shroud to flanges on sides of radi-
ator. Install fan shroud mounting bolts (Fig. 37).
Tighten bolts to 6 N´m (50 in. lbs.) torque.
(8) Install coolant reserve/overflow tank hose to
radiator filler neck nipple.
(9) Connect the overflow hose to the radiator.
(10) Install battery negative cables.
(11) Position heater controls tofull heatposition.
(12) Fill cooling system with coolant (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(13) Operate engine until it reaches normal tem-
perature. Check cooling system fluid levels.
RADIATOR - 5.9L DIESEL
DESCRIPTION
The radiator is a aluminum cross-flow design with
horizontal tubes through the radiator core and verti-
cal plastic side tanks (Fig. 39).
This radiator contains an internal transmission oil
cooler only on the V-10 gas engine and the 5.9L die-
sel engine combinations.
OPERATION
The radiator supplies sufficient heat transfer using
the cooling fins interlaced between the horizontal
tubes in the radiator core to cool the engine.
DIAGNOSIS AND TESTINGÐRADIATOR
COOLANT FLOW
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 PRES-
SURE BUILD-UP HAS BEEN RELEASED, REMOVE
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
operating temperature. If coolant is flowing past the
exposed tubes, the coolant is circulating.
REMOVAL
(1) Disconnect both battery negative cables.
Remove the nuts retaining the positive cable to the
top of radiator. Position positive battery cable to rear
of vehicle.
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 7 - COOL-
ING - STANDARD PROCEDURE).
Fig. 39 Cross Flow RadiatorÐTypical
1 - COOLING TUBES
2 - TANKS
BR/BEENGINE 7 - 63
RADIATOR - 8.0L (Continued)

WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094). SNAP-ON CLAMP TOOL (NUMBER HPC-20)
MAY BE USED FOR LARGER CLAMPS. ALWAYS
WEAR SAFETY GLASSES WHEN SERVICING CON-
STANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps. If replacement
is necessary, use only an original equipment clamp
with a matching number or letter.
(3) Remove hose clamps and hoses from radiator.
(4) Remove coolant reserve/overflow tank hose
from radiator filler neck nipple.
(5) Remove the coolant reserve/overflow tank from
the fan shroud (pull straight up). The tank slips into
T-slots on the fan shroud (Fig. 40). The coolant recov-
ery/reservoir does not require removal. Disconnect
the overflow hose from the radiator.
(6) Disconnect electrical connectors at windshield
washer reservoir tank and remove tank.
(7) Remove the two metal clips retaining the upper
part of fan shroud to the top of radiator.(8) Remove the four fan shroud mounting bolts
(Fig. 41). Position shroud rearward over the fan
blades towards engine.
(9) Remove the two radiator upper mounting bolts
(Fig. 42).
Fig. 40 Coolant Recovery BottleÐTypical
1 - T-SLOTS
2 - ALIGNMENT PIN
3 - FAN SHROUD
4 - COOLANT RESERVE/OVERFLOW TANK
Fig. 41 Fan Shroud MountingÐ5.9L Diesel Engine
1 - RADIATOR SUPPORT
2 - RADIATOR
3 - BOLTS (4)
4 - FAN SHROUD
Fig. 42 Typical Radiator Mounting
1 - MOUNTING BOLTS
2 - RADIATOR
3 - ALIGNMENT DOWELS (2)
4 - RADIATOR SUPPORT
7 - 64 ENGINEBR/BE
RADIATOR - 5.9L DIESEL (Continued)

(10) Lift radiator straight up and out of engine
compartment. The bottom of the radiator is equipped
with two alignment dowels that fit into holes in the
lower radiator support panel (Fig. 42). Rubber bis-
cuits (insulators) are installed to these dowels. Take
care not to damage cooling fins or tubes on the radi-
ator and air conditioning condenser when removing.
CLEANING
Clean radiator fins are necessary for good heat
transfer. The radiator and air conditioning fins
should be cleaned when an accumulation of debris
has occurred. With the engine cold, apply cold water
and compressed air to the back (engine side) of the
radiator to flush the radiator and/or A/C condenser of
debris.
INSPECTION
Inspect the radiator side tanks for cracks, broken
or missing fittings also inspect the joint where the
tanks seam up to the radiator core for signs of leak-
age and/or deteriorating seals.
Inspect radiator core for corroded, bent or missing
cooling fins. Inspect the core for bent or damaged
cooling tubes.
INSTALLATION
(1) Position fan shroud over the fan blades rear-
ward towards engine.
(2) Install rubber insulators to alignment dowels
at lower part of radiator.
(3) Lower the radiator into position while guiding
the two alignment dowels into lower radiator sup-
port. Different alignment holes are provided in the
lower radiator support for each engine application.
(4) Install two upper radiator mounting bolts.
Tighten bolts to 11 N´m (95 in. lbs.) torque.
(5) Connect both radiator hoses and install hose
clamps.
(6) Connect transmission cooler lines to radiator
tank. Inspect quick connect fittings for debris and
install until an audible ªclickº is heard. Pull apart to
verify connection.
(7) Install windshield washer reservoir tank.
(8) Position fan shroud to flanges on sides of radi-
ator. Install fan shroud mounting bolts (Fig. 41).
Tighten bolts to 6 N´m (50 in. lbs.) torque.
(9) Install metal clips to top of fan shroud.
(10) Install coolant reserve/overflow tank hose to
radiator filler neck nipple.
(11) Install coolant reserve/overflow tank to fan
shroud (fits into T-slots on shroud).
(12) Install battery negative cables.
(13) Install positive battery cable to top of radia-
tor. Tighten radiator-to-battery cable mounting nuts.
(14) Position heater controls tofull heatposition.(15) Fill cooling system with coolant (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(16) Operate engine until it reaches normal tem-
perature. Check cooling system and automatic trans-
mission (if equipped) fluid levels.
RADIATOR PRESSURE CAP
DESCRIPTION
Radiators are equipped with a pressure cap, which
releases pressure at some point within a range of
97-124 kPa (14-18 psi). The pressure relief point (in
pounds) is engraved on top of cap.
The cooling system will operate at pressures
slightly above atmospheric pressure. This results in a
higher coolant boiling point allowing increased radi-
ator cooling capacity.
A rubber gasket seals radiator filler neck to pre-
vent leakage. This is done to keep system under
pressure. It also maintains vacuum during coolant
cool-down allowing coolant to return from reserve/
overflow tank.
OPERATION
The cap (Fig. 43) contains a spring-loaded pressure
relief valve that opens when system pressure reaches
release range of 97-124 kPa (14-18 psi).
A vent valve in the center of cap allows a small
coolant flow through cap when coolant is below boil-
ing temperature. The valve is completely closed when
boiling point is reached. As the coolant cools, it con-
Fig. 43 Radiator Pressure Cap and Filler NeckÐ
Typical
1 - STAINLESS-STEEL SWIVEL TOP
2 - RUBBER SEALS
3 - VENT VALVE
4 - RADIATOR TANK
5 - FILLER NECK
6 - OVERFLOW NIPPLE
7 - MAIN SPRING
8 - GASKET RETAINER
BR/BEENGINE 7 - 65
RADIATOR - 5.9L DIESEL (Continued)

(9) Re-install the thermostat cover onto the oil
cooler and install the snap-ring.
(10) Re-connect the oil cooler to the transmission
cooler lines.
(11) Turn pump ON for two to three minutes to
flush cooler(s) and lines.
NOTE: This flushes the bypass circuit of the cooler
only.
(12) Turn pump OFF.
(13) Remove the thermostat cover from the oil
cooler.
(14) Install Special Tool Cooler Plug 8414 into the
transmission oil cooler.
(15) Re-install the thermostat cover onto the oil
cooler and install the snap-ring.
(16) Turn pump ON for two to three minutes to
flush cooler(s) and lines.
NOTE: This flushes the main oil cooler core pas-
sages only.
(17) Turn pump OFF.
(18) Remove the thermostat cover from the oil
cooler.
(19) Remove Special Tool Cooler Plug 8414 from
the transmission oil cooler.
(20) Install a new thermostat spring, thermostat,
cover, and snap-ring into the transmission oil cooler.
(Refer to 7 - COOLING/TRANSMISSION/TRANS
COOLER - ASSEMBLY)
(21) Install the transmission oil cooler onto the
vehicle. (Refer to 7 - COOLING/TRANSMISSION/
TRANS COOLER - INSTALLATION)
(22) Disconnect CLEAR suction line from reservoir
at cover plate. Disconnect CLEAR return line at
cover plate, and place it in a drain pan.
(23) Turn pump ON for 30 seconds to purge flush-
ing solution from cooler and lines. Turn pump OFF.
(24) Place CLEAR suction line into a one quart
container of MopartATF +4, type 9602, Automatic
Transmission fluid.
(25) Turn pump ON until all transmission fluid is
removed from the one quart container and lines. This
purges any residual cleaning solvent from the trans-
mission cooler and lines. Turn pump OFF.
(26) Disconnect alligator clips from battery. Recon-
nect flusher lines to cover plate, and remove flushing
adapters from cooler lines.
REMOVALÐAIR TO OIL COOLER
(1) Remove front bumper.
(2) Place a drain pan under the oil cooler.
(3) Raise the vehicle.
(4) Disconnect the oil cooler quick-connect fittings
from the transmission lines.(5) Remove the charge air cooler-to-oil cooler bolt
(Fig. 8).
(6) Remove two mounting nuts.
(7) Remove the oil cooler and line assembly
towards the front of vehicle. Cooler must be rotated
and tilted into position while removing.
REMOVALÐWATER TO OIL COOLER
CAUTION: If a leak should occur in the water-to-oil
cooler mounted to the side of the engine block,
engine coolant may become mixed with transmis-
sion fluid. Transmission fluid may also enter engine
cooling system. Both cooling system and transmis-
sion should be drained and inspected in case of oil
cooler leakage.
(1) Disconnect both battery negative cables.
(2) Remove air cleaner assembly and air cleaner
intake hoses.
(3) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(4) Disconnect coolant lines from cooler.
(5) Disconnect transmission oil lines from cooler.
Plug cooler lines to prevent oil leakage.
(6) Remove oil cooler mounting straps (Fig. 9).
Fig. 8 Auxiliary Transmission Oil CoolerÐDiesel
Engine
1 - CHARGE AIR COOLER (INTERCOOLER)
2 - QUICK-CONNECT FITTINGS (2)
3 - MOUNTING NUTS (2)
4 - MOUNTING BOLT
5 - TRANSMISSION OIL COOLER
BR/BETRANSMISSION 7 - 87
TRANS COOLER - 5.9L DIESEL (Continued)

²Wiper motor.
If the source of RFI or EMI noise is identified as a
component on the vehicle (i.e., generator, blower
motor, etc.), the ground path for that component
should be checked. If excessive resistance is found in
any ground circuit, clean, tighten, or repair the
ground circuits or connections to ground as required
before considering any component replacement.
For service and inspection of secondary ignition
components, refer to Electrical, Ignition Control.
Inspect the following secondary ignition system com-
ponents:
²Distributor cap and rotor
²Ignition coil
²Spark plugs
²Spark plug wire routing and condition.
Reroute the spark plug wires or replace the faulty
components as required.
If the source of the RFI or EMI noise is identified
as two-way mobile radio or telephone equipment,
check the equipment installation for the following:
²Power connections should be made directly to
the battery, and fused as closely to the battery as
possible.
²The antenna should be mounted on the roof or
toward the rear of the vehicle. Remember that mag-
netic antenna mounts on the roof panel can adversely
affect the operation of an overhead console compass,
if the vehicle is so equipped.
²The antenna cable should be fully shielded coax-
ial cable, should be as short as is practical, and
should be routed away from the factory-installed
vehicle wire harnesses whenever possible.
²The antenna and cable must be carefully
matched to ensure a low Standing Wave Ratio
(SWR).
Fleet vehicles are available with an extra-cost RFI-
suppressed Powertrain Control Module (PCM). This
unit reduces interference generated by the PCM on
some radio frequencies used in two-way radio com-
munications. However, this unit will not resolve com-
plaints of RFI in the commercial AM or FM radio
frequency ranges.
ENGINE-TO-BODY GROUND
STRAP
REMOVAL
(1) Remove the screw that secures the engine-to-
body ground strap eyelet to the dash panel (Fig. 10).
(2) Remove the screw that secures the engine-to-
body ground strap eyelet to the back of the engine
cylinder head (Fig. 11) or (Fig. 12).
(3) For the right side only on vehicles equipped
with a 3.9L, 5.2L or 5.9L engine, remove the nut thatsecures the engine-to-body ground strap eyelet to the
right rear valve cover stud.
(4) Remove the engine-to-body ground strap from
the engine compartment.INSTALLATION
(1) Position the engine-to-body ground strap to the
back of the engine cylinder head.
(2) Install and tighten the screw that secures the
engine-to-body ground strap eyelet to the back of the
engine cylinder head. Tighten the screw to 3.9 N´m
(35 in. lbs.).
Fig. 10 Engine-To-Body Ground
1 - SCREWS (2)
2 - GROUND STRAPS
Fig. 11 Engine-To-Body Ground Strap Remove/
Install - V6 & V8 Engine
1 - GROUND STRAP
2 - NUT
3 - GROUND STRAP
4 - SCREW
5 - SCREW
BR/BEAUDIO 8A - 13
RADIO NOISE SUPPRESSION COMPONENTS (Continued)

(5) Disengage the four remote radio switch latches
that secure the switch to the inside of the mounting
hole in the steering wheel rear trim cover .
(6) From the outside of the steering wheel rear
trim cover, remove the remote radio switch from the
trim cover mounting hole.
INSTALLATION
(1) Position the remote radio switch to the mount-
ing hole on the outside of the steering wheel rear
trim cover. Be certain that the connector receptacle is
oriented toward the bottom of the switch and pointed
toward the center of the steering wheel.
(2) Press firmly and evenly on the remote radio
switch until each of the switch latches is fully
engaged in the mounting hole of the steering wheel
rear trim cover.
(3) Reconnect the steering wheel wire harness con-
nector to the connector receptacle of the remote radio
switch.
(4) Install the speed control switch onto the steer-
ing wheel. Refer to Electrical, Speed Control for the
procedures.(5) Install the driver side airbag module onto the
steering wheel. Refer to Electrical, Restraints for the
procedures.
(6) Reconnect the battery negative cable.
SPEAKER
DESCRIPTION
STANDARD
The standard equipment speaker system includes
speakers in four locations. One full-range 15.2 by
22.9 centimeter (6.0 by 9.0 inch) speaker is located in
each front door. There is also one full-range 13.3 cen-
timeter (5.25 inch) diameter speaker located in each
rear cab side panel for the standard cab and the club
cab models, or in each rear door of the quad cab mod-
els.
PREMIUM
The optional premium speaker system features
Infinity model speakers in six locations. Each of the
standard front door speakers are replaced with Infin-
ity model speakers that include integral dual 30 watt
amplifiers. Each of the standard rear speakers is also
replaced by an Infinity model speaker. The premium
speaker system also includes an additional Infinity
tweeter mounted in the A-pillar garnish molding. The
total available power of the premium speaker system
is about 120 watts.
OPERATION
STANDARD
Each of the four full-range speakers used in the
standard speaker system is driven by the amplifier
that is integral to the factory-installed radio receiver.
For complete circuit diagrams, refer to the appropri-
ate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds.
Fig. 17 Remote Radio Switches Remove/Install
1 - STEERING WHEEL
2 - REMOTE RADIO SWITCH
3 - SPEED CONTROL SWITCH
4 - SCREW (2)
5 - DRIVER SIDE AIRBAG MODULE
6 - SPEED CONTROL SWITCH
7 - REAR TRIM COVER
8 - SCREW (2)
BR/BEAUDIO 8A - 17
REMOTE SWITCHES (Continued)