2003 DODGE RAM light

(4) Press firmly on the cigar lighter or power out-
let receptacle base until the retaining bosses of the
mount are fully engaged in their receptacles.
(5) Install the cigar lighter knob and element into
the cigar lighter receptacle base, or the protective cap
into the power outlet receptacle base.
(6) Reconnect the battery negative cable.
RELAY
DESCRIPTION
A relay (Fig. 8) is an electromechanical device that
switches fused battery current to a electrical compo-
nent when the ignition switch is turned to the Acces-
sory or Run positions, or when controlled by a
electronic module. The relays are located in the inte-
grated power module.
The relay is a International Standards Organiza-
tion (ISO) relay. Relays conforming to the ISO speci-
fications have common physical dimensions, current
capacities, terminal patterns, and terminal functions.
A relay cannot be repaired or adjusted and, if
faulty or damaged, it must be replaced.
OPERATION
The ISO relay consists of an electromagnetic coil, a
resistor and three (two fixed and one movable) elec-
trical contacts. The movable (common feed) relay con-
tact is held against one of the fixed contacts
(normally closed) by spring pressure. When the elec-
tromagnetic coil is energized, it draws the movable
contact away from the normally closed fixed contact,
and holds it against the other (normally open) fixed
contact.
When the electromagnetic coil is de-energized,
spring pressure returns the movable contact to the
normally closed position. The resistor is connected in
parallel with the electromagnetic coil in the relay,
and helps to dissipate voltage spikes that are pro-
duced when the coil is de-energized.
DIAGNOSIS AND TESTING - RELAY
The relays are located in the integrated power
module. For complete circuit diagrams, refer toWir-
ing Diagrams.
(1) Remove the relay from its mounting location.
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 60.7 - 80.3 ohms. If OK, go to
Step 4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, perform the Relay Circuit Test that
follows. If not OK, replace the faulty relay.
Fig. 7 Cigar Lighter and Power Outlet Remove/
Install
1 - KNOB AND ELEMENT
2 - RETAINING BOSSES-ENGAGE PLIERS HERE
3 - BASE
4 - PARTIALLY REMOVED
5 - EXTERNAL SNAP-RING PLIERS
6 - MOUNT
7 - BASE
Fig. 8 ISO Relay
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
8W - 97 - 8 8W-97 POWER DISTRIBUTIONDR
POWER OUTLET (Continued)

DIAGNOSIS & TESTING - RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) of
the integrated power module is connected to battery
voltage and should be hot at all times. Check for bat-
tery voltage at the fused B(+) circuit cavity in the
integrated power module receptacle for the relay. If
OK, go to Step 2. If not OK, repair the fused B(+) cir-
cuit to the integrated power module fuse as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the fused B(+) fuse in the integrated power module
that feeds the accessory when the relay is energized
by the ignition switch. There should be continuity
between the integrated power module cavity for relay
terminal 87 and the fused B(+) fuse in the integrated
power module at all times. If OK, go to Step 4. If not
OK, repair the open fused B(+) circuit to the inte-
grated power module fuse as required.
(4) The coil ground terminal (85) is connected to
the electromagnet in the relay. It receives battery
feed to energize the relay when the ignition switch is
in the Accessory or Run positions. Turn the ignition
switch to the On position. Check for battery voltage
at the fused ignition switch output (acc/run) circuit
cavity for relay terminal 85 in the integrated power
module receptacle for the relay. If OK, go to Step 5. If
not OK, repair the open fused ignition switch output
(acc/run) circuit to the ignition switch as required.
(5) The coil battery terminal (86) is connected to
the electromagnet in the relay. The integrated power
module cavity for this terminal should have continu-
ity to ground at all times. If not OK, repair the open
ground circuit to ground as required.
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the relay by grasping it firmly and
pulling it straight out from its receptacle. A slight
back and fourth rocking motion may help the
removal process.
INSTALLATION
(1) Position the relay to the proper receptacle.
(2) Align the relay terminals with the terminal
cavities in the receptacle.
(3) Push firmly and evenly on the top of the relay
until the terminals are fully seated in the terminal
cavities in the receptacle.
(4) Connect the negative battery cable.
MICRO RELAY
DESCRIPTION
A micro-relay is a conventional International Stan-
dards Organization (ISO) micro relay (Fig. 9). Relays
conforming to the ISO specifications have common
physical dimensions, current capacities, terminal pat-
terns, and terminal functions. The relay is contained
within a small, rectangular, molded plastic housing
and is connected to all of the required inputs and
outputs by five integral male spade-type terminals
that extend from the bottom of the relay base.
Relays cannot be adjusted or repaired and, if faulty
or damaged, the unit must be replaced.
OPERATION
A micro-relay is an electromechanical switch that
uses a low current input from one source to control a
high current output to another device. The movable
common feed contact point is held against the fixed
normally closed contact point by spring pressure.
When the relay coil is energized, an electromagnetic
field is produced by the coil windings. This electro-
magnetic field draws the movable relay contact point
away from the fixed normally closed contact point,
and holds it against the fixed normally open contact
point. When the relay coil is de-energized, spring
pressure returns the movable contact point back
against the fixed normally closed contact point. A
resistor is connected in parallel with the relay coil in
the relay, and helps to dissipate voltage spikes and
electromagnetic interference that can be generated as
the electromagnetic field of the relay coil collapses.
DIAGNOSIS AND TESTING - MICRO-RELAY
(1) Remove the relay from its mounting location.
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
Fig. 9 DR ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
DR8W-97 POWER DISTRIBUTION 8W - 97 - 9
RELAY (Continued)

no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 67.5 - 82.5 ohms. If OK, go to
Step 4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, reinstall the relay and use a DRB IIIt
scan tool to perform further testing. Refer to the
appropriate diagnostic information.
Refer to the appropriate 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 connectors, splices and grounds.REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the relay by grasping it firmly and
pulling it straight out from its receptacle. A slight
back and fourth rocking motion may help the
removal process.
INSTALLATION
(1) Align the micro-relay terminals with the termi-
nal cavities in the receptacle.
(2) Push firmly and evenly on the top of the relay
until the terminals are fully seated in the terminal
cavities in the receptacle.
(3) Connect the battery negative cable.
8W - 97 - 10 8W-97 POWER DISTRIBUTIONDR
MICRO RELAY (Continued)

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either per-
formance (e.g., engine idles rough and stalls) or
mechanical (e.g., a strange noise).
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING)ÐPERFORMANCE and (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)ÐMECHANICAL for
possible causes and corrections of malfunctions.
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
DIAGNOSIS AND TESTING) and (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION - DIAGNOSIS
AND TESTING) for the fuel system diagnosis.Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following diagnosis:
²Cylinder Compression Pressure Test (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).
²Cylinder Combustion Pressure Leakage Test
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING).
²Engine Cylinder Head Gasket Failure Diagnosis
(Refer to 9 - ENGINE/CYLINDER HEAD - DIAGNO-
SIS AND TESTING).
²Intake Manifold Leakage Diagnosis (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
DIAGNOSIS AND TESTING).
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery 1. Charge or replace as necessary.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to the terminals.
3. Faulty starter. 3. (Refer to 8 - ELECTRICAL/
STARTING - DIAGNOSIS AND
TESTING).
4. Faulty coil or control unit. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
5. Incorrect spark plug gap. 5. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
6. Incorrect right bank cam timing. 6. Refer to engine timing in this
section.
7. Dirt or water in fuel system. 7. Clean system and replace fuel
filter.
8.Faulty fuel pump, relay or wiring. 8.Repair or replace as necessary.
9. Faulty cam or crank sensor 9. Refer to Ignition system.
ENGINE STALLS OR ROUGH IDLE 1. Vacuum leak. 1. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
2. Faulty crank position sensor 2. Replace crank position sensor.
3. Faulty coil. 3. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
9 - 4 ENGINE - 3.7LDR
ENGINE - 3.7L (Continued)

(6) Remove the cylinder head cover mounting bolts
(Fig. 16).
(7) Remove cylinder head cover and gasket.
NOTE: The gasket may be used again, providing no
cuts, tears, or deformation has occurred.
INSTALLATION
CAUTION: Do not use harsh cleaners to clean the
cylinder head covers. Severe damage to covers
may occur.
NOTE: The gasket may be used again, provided no
cuts, tears, or deformation has occurred.
(1) Clean cylinder head cover and both sealing sur-
faces. Inspect and replace gasket as necessary.
(2) Tighten cylinder head cover bolts and double
ended studs to 12 N´m (105 in. lbs.).
(3) Install left side breather and connect breather
tube.
(4) Connect injector electrical connectors and injec-
tor harness retaining clips.(5) Install the resonator and air inlet hose.
(6) Connect negative cable to battery.
INTAKE/EXHAUST VALVES &
SEATS
DESCRIPTION
The valves are made of heat resistant steel and
have chrome plated stems to prevent scuffing. Each
valve is actuated by a roller rocker arm which pivots
on a stationary lash adjuster. All valves use three
bead lock keepers to retain the springs and promote
valve rotation.
STANDARD PROCEDURE - REFACING
NOTE: Valve seats that are worn or burned can be
reworked, provided that correct angle and seat
width are maintained. Otherwise the cylinder head
must be replaced.
NOTE: When refacing valves and valve seats, it is
important that the correct size valve guide pilot be
used for reseating stones. A true and complete sur-
face must be obtained.
(1) Using a suitable dial indicator measure the
center of the valve seat Total run out must not
exceed 0.051 mm (0.002 in).
(2) Apply a small amount of Prussian blue to the
valve seat, insert the valve into the cylinder head,
while applying light pressure on the valve rotate the
valve. Remove the valve and examine the valve face.
If the blue is transferred below the top edge of the
valve face, lower the valve seat using a 15 degree
stone. If the blue is transferred to the bottom edge of
the valve face, raise the valve seat using a 65 degree
stone.
(3) When the seat is properly positioned the width
of the intake seat must be 1.75 ± 2.36 mm (0.0689 ±
0.0928 in.) and the exhaust seat must be 1.71 ± 2.32
mm (0.0673 ± 0.0911 in.).
(4) Check the valve spring installed height after
refacing the valve and seat. The installed height for
both intake and exhaust valve springs must not
exceed 40.74 mm (1.6039 in.).
Fig. 16 CYLINDER HEAD COVER -TYPICAL
1 - SCREWS
2 - CYLINDER HEAD COVER
DRENGINE - 3.7L 9 - 27
CYLINDER HEAD COVER(S) (Continued)

REMOVAL
(1) Remove the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) Using Special Tool 8516 Valve Spring Compres-
sor, remove the rocker arms and the hydraulic lash
adjusters.
(3) Remove the spark plug for the cylinder the
valve spring and seal are to be removed from.
(4) Apply shop air to the cylinder to hold the
valves in place when the spring is removed.
NOTE: All six valve springs and seals are removed
in the same manner; this procedure only covers
one valve seal and valve spring.
(5) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
NOTE: It may be necessary to tap the top of the
valve spring to loosen the spring retainers locks
enough to be removed.
(6) Remove the two spring retainer lock halves.
NOTE: the valve spring is under tension use care
when releasing the valve spring compressor.
(7) Remove the valve spring compressor.
NOTE: The valve springs are NOT common between
intake and exhaust.
(8) Remove the spring retainer, and the spring.
(9) Remove the valve stem seal.
NOTE: The valve stem seals are common between
intake and exhaust.
INSTALLATION
NOTE: All six valve springs and seals are removed
in the same manner; this procedure only covers
one valve seal and valve spring.
(1) Apply shop air to the cylinder to hold the
valves in place while the spring is installed.
NOTE: The valve stem seals are common between
intake and exhaust.
(2) Install the valve stem seal.NOTE: The valve springs are NOT common between
intake and exhaust.
(3) Install the spring retainer, and the spring.
(4) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
(5) Install the two spring retainer lock halves.
NOTE: the valve spring is under tension use care
when releasing the valve spring compressor.
(6) Remove the valve spring compressor.
(7) Disconnect the shop air to the cylinder.
(8) Install the spark plug for the cylinder the valve
spring and seal was installed on.
(9) Using Special Tool 8516 Valve Spring Compres-
sor, install the rocker arms and the hydraulic lash
adjusters.
(10) Install the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
ENGINE BLOCK
DESCRIPTION
The cylinder block is made of cast iron. The block
is a closed deck design with the left bank forward. To
provide high rigidity and improved NVH an
enhanced compacted graphite bedplate is bolted to
the block. The block design allows coolant flow
between the cylinders bores, and an internal coolant
bypass to a single poppet inlet thermostat is included
in the cast aluminum front cover.
STANDARD PROCEDUREÐCYLINDER BORE
HONING
Before honing, stuff plenty of clean shop towels
under the bores and over the crankshaft to keep
abrasive materials from entering the crankshaft
area.
(1) Used carefully, the Cylinder Bore Sizing Hone
C-823, equipped with 220 grit stones, is the best tool
for this job. In addition to deglazing, it will reduce
taper and out-of-round, as well as removing light
scuffing, scoring and scratches. Usually, a few strokes
will clean up a bore and maintain the required lim-
its.
CAUTION: DO NOT use rigid type hones to remove
cylinder wall glaze.
DRENGINE - 3.7L 9 - 37
VALVE SPRINGS (Continued)

(2) Deglazing of the cylinder walls may be done if
the cylinder bore is straight and round. Use a cylin-
der surfacing hone, Honing Tool C-3501, equipped
with 280 grit stones (C-3501-3810). about 20-60
strokes, depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Using honing
oil C-3501-3880, or a light honing oil, available from
major oil distributors.
CAUTION: DO NOT use engine or transmission oil,
mineral spirits, or kerosene.
(3) Honing should be done by moving the hone up
and down fast enough to get a crosshatch pattern.
The hone marks should INTERSECT at 50É to 60É
for proper seating of rings (Fig. 29).
(4) A controlled hone motor speed between 200 and
300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 50É to 60É
angle. Faster up and down strokes increase the cross-
hatch angle.
(5) After honing, it is necessary that the block be
cleaned to remove all traces of abrasive. Use a brush
to wash parts with a solution of hot water and deter-
gent. Dry parts thoroughly. Use a clean, white, lint-
free cloth to check that the bore is clean. Oil the
bores after cleaning to prevent rusting.CLEANING
Thoroughly clean the oil pan and engine block gas-
ket surfaces.
Use compressed air to clean out:
²The galley at the oil filter adaptor hole.
²The front and rear oil galley holes.
²The feed holes for the crankshaft main bearings.
Once the block has been completely cleaned, apply
Loctite PST pipe sealant with Teflon 592 to the
threads of the front and rear oil galley plugs. Tighten
the 1/4 inch NPT plugs to 20 N´m (177 in. lbs.)
torque. Tighten the 3/8 inch NPT plugs to 27 N´m
(240 in. lbs.) torque.
INSPECTION
(1) It is mandatory to use a dial bore gauge to
measure each cylinder bore diameter. To correctly
select the proper size piston, a cylinder bore gauge,
capable of reading in 0.003 mm (.0001 in.) INCRE-
MENTS is required. If a bore gauge is not available,
do not use an inside micrometer (Fig. 30).
(2) Measure the inside diameter of the cylinder
bore at three levels below top of bore. Start perpen-
dicular (across or at 90 degrees) to the axis of the
crankshaft and then take two additional reading.
(3) Measure the cylinder bore diameter crosswise
to the cylinder block near the top of the bore. Repeat
the measurement near the middle of the bore, then
repeat the measurement near the bottom of the bore.
Fig. 29 CYLINDER BORE CROSSHATCH PATTERN
1 - CROSSHATCH PATTERN
2 - INTERSECT ANGLE
Fig. 30 BORE GAUGE-TYPICAL
1 - FRONT
2 - BORE GAUGE
3 - CYLINDER BORE
4 - 38 MM (1.5 in)
9 - 38 ENGINE - 3.7LDR
ENGINE BLOCK (Continued)

(4) Determine taper by subtracting the smaller
diameter from the larger diameter.
(5) Rotate measuring device 90É and repeat steps
above.
(6) Determine out-of-roundness by comparing the
difference between each measurement.
(7) If cylinder bore taper does not exceed 0.025
mm (0.001 inch) and out-of-roundness does not
exceed 0.025 mm (0.001 inch), the cylinder bore can
be honed. If the cylinder bore taper or out- of-round
condition exceeds these maximum limits, the cylinder
block must be replaced. A slight amount of taper
always exists in the cylinder bore after the engine
has been in use for a period of time.
CRANKSHAFT
DESCRIPTION
The crankshaft is constructed of nodular cast iron.
The crankshaft is a three throw split pin design with
six counterweights for balancing purposes. The
crankshaft is supported by four select fit main bear-
ings with the number two serving as the thrust
washer location. The main journals of the crankshaft
are cross drilled to improve rod bearing lubrication.
The number six counterweight has provisions for
crankshaft position sensor target wheel mounting.
The select fit main bearing markings are located on
the rear side of the target wheel (Fig. 31). The crank-
shaft oil seals are one piece design. The front oil seal
is retained in the timing chain cover, and the rear
seal is pressed in to a bore formed by the cylinder
block and the bedplate assembly.
REMOVAL
NOTE: To remove the crankshaft from the engine,
the engine must be removed from the vehicle.
(1) Remove the engine(Refer to 9 - ENGINE -
REMOVAL).
(2) Remove the engine oil pump(Refer to 9 -
ENGINE/LUBRICATION/OIL PUMP - REMOVAL).
CAUTION: DO NOT pry on the oil pan gasket when
removing the oil pan, The oil pan gasket is mounted
to the cylinder block in three locations and will
remain attached to block when removing oil pan.
Gasket can not be removed with oil pan.
(3) Remove the bedplate mounting bolts. Note the
location of the two stud bolts for installation.
(4) Remove the connecting rods from the crank-
shaft.CAUTION: The bedplate to cylinder block mating
surface is a critical sealing surface. Do not pry on
or damage this surface in anyway.
NOTE: The bedplate contains the lower main bear-
ing halves. Use care when handling bedplate as not
to drop or damage bearing halves. Installing main
bearing halves in the wrong position will cause
severe damage to the crankshaft.
NOTE: The bedplate has pry points cast into it. Use
these points only. The pry points are shown below.
(5) Carefully pry on the pry points (Fig. 32) to
loosen the bedplate then remove the bedplate.
CAUTION: When removing the crankshaft, use care
not to damage bearing surfaces on the crankshaft.
(6) Remove the crankshaft.
(7) Remove the crankshaft tone wheel.
Fig. 31 CRANKSHAFT AND TARGET RING
1 - CRANKSHAFT
2 - CRANKSHAFT POSITION SENSOR TARGET RING
DRENGINE - 3.7L 9 - 39
ENGINE BLOCK (Continued)