2003 DODGE RAM charging

5.7L
WARNING: DISCONNECT NEGATIVE CABLE FROM
BATTERY BEFORE REMOVING BATTERY OUTPUT
WIRE (B+ WIRE) FROM GENERATOR. FAILURE TO
DO SO CAN RESULT IN INJURY OR DAMAGE TO
ELECTRICAL SYSTEM.
(1) Disconnect negative battery cable at battery.
(2) Remove generator drive belt. Refer to 7, Cool-
ing System for procedure.
(3) Unsnap plastic insulator cap from B+ output
terminal.
(4) Remove B+ terminal mounting nut at rear of
generator. Disconnect terminal from generator.
(5) Disconnect field wire connector at rear of gen-
erator by pushing on connector tab.
(6) Remove generator support bracket nuts and
bolt (Fig. 4) and remove support bracket.
(7) Remove 2 generator mounting bolts (Fig. 5).
(8) Remove generator from vehicle.
5.9L Diesel
WARNING: DISCONNECT BOTH NEGATIVE CABLES
FROM BOTH BATTERIES BEFORE REMOVING BAT-
TERY OUTPUT WIRE (B+ WIRE) FROM GENERA-
TOR. FAILURE TO DO SO CAN RESULT IN INJURY
OR DAMAGE TO ELECTRICAL SYSTEM.(1) Disconnect both negative battery cables at both
batteries.
(2) Remove generator drive belt. Refer to 7, Cool-
ing System for procedure.
(3) Unsnap plastic insulator cap from B+ output
terminal.
(4) Remove B+ terminal mounting nut at rear of
generator (Fig. 7). Disconnect terminal from genera-
tor.
(5) Disconnect field wire connector at rear of gen-
erator by pushing on connector tab.
(6) Remove upper mounting bracket bolt (Fig. 6).
(7) Remove lower mounting bracket bolt and nut
(Fig. 6).
(8) Remove generator from vehicle.
5.9L Gas
WARNING: DISCONNECT NEGATIVE CABLE FROM
BATTERY BEFORE REMOVING BATTERY OUTPUT
WIRE (B+ WIRE) FROM GENERATOR. FAILURE TO
DO SO CAN RESULT IN INJURY OR DAMAGE TO
ELECTRICAL SYSTEM.
(1) Disconnect negative battery cable at battery.
(2) Remove generator drive belt. Refer to 7, Cool-
ing System for procedure.
Fig. 4 GENERATOR SUPPORT BRACKET- 5.7L
1 - GENERATOR
2 - SUPPORT BRACKET
3 - BRACKET NUTS
4 - BRACKET BOLT
Fig. 5 REMOVE / INSTALL GENERATOR - 5.7L
1 - MOUNTING BOLT
2 - GENERATOR
3 - MOUNTING STUD / BOLT
DRCHARGING 8F - 23
GENERATOR (Continued)

(3) Unsnap plastic insulator cap from B+ output
terminal (Fig. 8).(4) Remove B+ terminal mounting nut at rear of
generator (Fig. 8). Disconnect terminal from genera-
tor.
(5) Disconnect field wire connector at rear of gen-
erator (Fig. 8) by pushing on connector tab.
(6) Remove 1 upper generator mounting bolt (Fig.
9).
(7) Remove 1 lower generator mounting bolt / nut
(Fig. 9).
(8) Remove generator from vehicle.
8.0L
WARNING: DISCONNECT NEGATIVE CABLE FROM
BATTERY BEFORE REMOVING BATTERY OUTPUT
WIRE (B+ WIRE) FROM GENERATOR. FAILURE TO
DO SO CAN RESULT IN INJURY OR DAMAGE TO
ELECTRICAL SYSTEM.
(1) Disconnect negative battery cable at battery.
(2) Remove generator drive belt. Refer to 7, Cool-
ing System for procedure.
(3) Unsnap plastic insulator cap from B+ output
terminal.
(4) Remove B+ terminal mounting nut at rear of
generator. Disconnect terminal from generator.
(5) Disconnect field wire connector at rear of gen-
erator by pushing on connector tab.
(6) Remove upper mounting bolt and nut (Fig. 10).
(7) Remove lower mounting bolt (Fig. 10).
Fig. 6 5.9L DIESEL GENERATOR
1 - GENERATOR
2 - MOUNTING BOLTS
Fig. 7 5.9L DIESEL GENER. CONNECTORS
1 - B+ CONNECTOR
2 - GENERATOR
3 - FIELD WIRE CONNECTOR
Fig. 8 GENERATOR CONNECTORS - 5.9L GAS
1 - PLASTIC INSULATOR CAP
2 - FIELD WIRE CONNECTOR
3 - GENERATOR
4-B+NUT
8F - 24 CHARGINGDR
GENERATOR (Continued)

(8) Remove generator from vehicle.
INSTALLATION
3.7L / 4.7L
(1) Position generator to engine and install 2 hor-
izontal bolts and 1 vertical bolt.
(2) Tighten all 3 bolts. Refer to Torque Specifica-
tions.
(3) Snap field wire connector into rear of genera-
tor.
(4) Install B+ terminal eyelet to generator output
stud. Tighten mounting nut. Refer to Torque Specifi-
cations.
CAUTION: Never force a belt over a pulley rim
using a screwdriver. The synthetic fiber of the belt
can be damaged.
CAUTION: When installing a serpentine accessory
drive belt, the belt MUST be routed correctly. The
water pump may be rotating in the wrong direction
if the belt is installed incorrectly, causing the
engine to overheat. Refer to belt routing label in
engine compartment, or refer to Belt Schematics in
7, Cooling System.
(5) Install generator drive belt. Refer to 7, Cooling
System for procedure.
(6) Install negative battery cable to battery.
5.7L
(1) Position generator to engine and install 2
mounting bolts.
(2) Tighten bolts. Refer to Torque Specifications.
(3) Position support bracket to front of generator
and install bolt and nuts. Tighten bolt / nuts. Refer
to Torque Specifications.
(4) Snap field wire connector into rear of genera-
tor.
(5) Install B+ terminal eyelet to generator output
stud. Tighten mounting nut. Refer to Torque Specifi-
cations.
CAUTION: Never force a belt over a pulley rim
using a screwdriver. The synthetic fiber of the belt
can be damaged.
CAUTION: When installing a serpentine accessory
drive belt, the belt MUST be routed correctly. The
water pump may be rotating in the wrong direction
if the belt is installed incorrectly, causing the
engine to overheat. Refer to belt routing label in
engine compartment, or refer to Belt Schematics in
7, Cooling System.
(6) Install generator drive belt. Refer to 7, Cooling
System for procedure.
Fig. 9 REMOVE / INSTALL GENERATOR - 5.9L GAS
1 - MOUNTING BOLT
2 - GENERATOR
3 - MOUNTING BRACKET
4 - MOUNTING BOLT/NUT
Fig. 10 REMOVE / INSTALL GENERATOR ± 8.0L
ENGINE
1 - MOUNTING BOLT
2 - GENERATOR
3 - NUT
4 - MOUNTING BRACKET
5 - MOUNTING BOLT
DRCHARGING 8F - 25
GENERATOR (Continued)

(7) Install negative battery cable to battery.
5.9L Diesel
(1) Position generator to upper and lower mount-
ing brackets and install upper bolt and lower bolt /
nut.
(2) Tighten all bolts / nut. Refer to Torque Specifi-
cations.
(3) Snap field wire connector into rear of genera-
tor.
(4) Install B+ terminal eyelet to generator output
stud. Tighten mounting nut. Refer to Torque Specifi-
cations.
CAUTION: Never force a belt over a pulley rim
using a screwdriver. The synthetic fiber of the belt
can be damaged.
CAUTION: When installing a serpentine accessory
drive belt, the belt MUST be routed correctly. The
water pump may be rotating in the wrong direction
if the belt is installed incorrectly, causing the
engine to overheat. Refer to belt routing label in
engine compartment, or refer to Belt Schematics in
7, Cooling System.
(5) Install generator drive belt. Refer to 7, Cooling
System for procedure.
(6) Install both negative battery cables to both bat-
teries.
8.0L
(1) Position generator to engine and install lower
bolt and upper bolt / nut.
(2) Tighten all bolts / nut. Refer to Torque Specifi-
cations.
(3) Snap field wire connector into rear of genera-
tor.
(4) Install B+ terminal eyelet to generator output
stud. Tighten mounting nut. Refer to Torque Specifi-
cations.
CAUTION: Never force a belt over a pulley rim
using a screwdriver. The synthetic fiber of the belt
can be damaged.CAUTION: When installing a serpentine accessory
drive belt, the belt MUST be routed correctly. The
water pump may be rotating in the wrong direction
if the belt is installed incorrectly, causing the
engine to overheat. Refer to belt routing label in
engine compartment, or refer to Belt Schematics in
7, Cooling System.
(5) Install generator drive belt. Refer to 7, Cooling
System for procedure.
(6) Install negative battery cable to battery.
5.9L Gas
(1) Position generator to engine and install upper
bolt and lower bolt / nut.
(2) Tighten all bolts / nut. Refer to Torque Specifi-
cations.
(3) Snap field wire connector into rear of genera-
tor.
(4) Install B+ terminal eyelet to generator output
stud. Tighten mounting nut. Refer to Torque Specifi-
cations.
CAUTION: Never force a belt over a pulley rim
using a screwdriver. The synthetic fiber of the belt
can be damaged.
CAUTION: When installing a serpentine accessory
drive belt, the belt MUST be routed correctly. The
water pump may be rotating in the wrong direction
if the belt is installed incorrectly, causing the
engine to overheat. Refer to belt routing label in
engine compartment, or refer to Belt Schematics in
7, Cooling System.
(5) Install generator drive belt. Refer to 7, Cooling
System for procedure.
(6) Install negative battery cable to battery.
8F - 26 CHARGINGDR
GENERATOR (Continued)

VOLTAGE REGULATOR
DESCRIPTION
The Electronic Voltage Regulator (EVR) is not a
separate component. It is actually a voltage regulat-
ing circuit located within the PCM (Powertrain Con-
trol Module) (within the ECM for diesel engines). The
EVR is not serviced separately. If replacement is nec-
essary, the PCM must be replaced.
OPERATION
The amount of direct current produced by the gen-
erator is controlled by EVR circuitry contained
within the PCM. This circuitry is connected in series
with the generators second rotor field terminal and
its ground.
Voltage is regulated by cycling the ground path to
control the strength of the rotor magnetic field. TheEVR circuitry monitors system line voltage (B+) and
battery temperature (refer to Battery Temperature
Sensor for more information). It then determines a
target charging voltage. If sensed battery voltage is
0.5 volts or lower than the target voltage, the PCM
grounds the field winding until sensed battery volt-
age is 0.5 volts above target voltage. A circuit in the
PCM cycles the ground side of the generator field up
to 100 times per second (100Hz), but has the capabil-
ity to ground the field control wire 100% of the time
(full field) to achieve the target voltage. If the charg-
ing rate cannot be monitored (limp-in), a duty cycle
of 25% is used by the PCM in order to have some
generator output. Also refer to Charging System
Operation for additional information.
DRCHARGING 8F - 27

STARTING
TABLE OF CONTENTS
page page
STARTING
DESCRIPTION.........................28
OPERATION...........................28
DIAGNOSIS AND TESTING - STARTING
SYSTEM............................29
SPECIFICATIONS
STARTING SYSTEM...................33
SPECIFICATIONS - TORQUE - STARTING
SYSTEM............................34
STARTER MOTOR
DIAGNOSIS AND TESTING - STARTER
MOTOR .............................34REMOVAL.............................34
INSTALLATION.........................37
STARTER MOTOR RELAY
DESCRIPTION.........................38
OPERATION...........................38
DIAGNOSIS AND TESTING - STARTER RELAY . 38
REMOVAL.............................39
INSTALLATION.........................39
STARTING
DESCRIPTION
The starting system consists of:
²Starter relay
²Starter motor (including an integral starter sole-
noid)
Other components to be considered as part of start-
ing system are:
²Battery
²Battery cables
²Ignition switch and key lock cylinder
²Clutch pedal position switch (manual transmis-
sion)
²Park/neutral position switch (automatic trans-
mission)
²Wire harnesses and connections.
The Battery, Starting, and Charging systems oper-
ate in conjunction with one another, and must be
tested as a complete system. For correct operation of
starting/charging systems, all components used in
these 3 systems must perform within specifications.
When attempting to diagnose any of these systems, it
is important that you keep their interdependency in
mind.
The diagnostic procedures used in each of these
groups include the most basic conventional diagnostic
methods, to the more sophisticated On-Board Diag-
nostics (OBD) built into the Powertrain Control Mod-
ule (PCM). Use of an induction-type milliampere
ammeter, volt/ohmmeter, battery charger, carbon pile
rheostat (load tester), and 12-volt test lamp may be
required.
Certain starting system components are monitored
by the PCM and may produce a Diagnostic TroubleCode (DTC). Refer to Diagnostic Trouble Codes in
Emission Control for a list of codes.OPERATION
The starting system components form two separate
circuits. A high-amperage feed circuit that feeds the
starter motor between 150 and 350 amperes (700
amperes - diesel engine), and a low-amperage control
circuit that operates on less than 20 amperes. The
high-amperage feed circuit components include the
battery, the battery cables, the contact disc portion of
the starter solenoid, and the starter motor. The low-
amperage control circuit components include the igni-
tion switch, the clutch pedal position switch (manual
transmission), the park/neutral position switch (auto-
matic transmission), the starter relay, the electro-
magnetic windings of the starter solenoid, and the
connecting wire harness components.
If the vehicle is equipped with a manual transmis-
sion, it has a clutch pedal position switch installed in
series between the ignition switch and the coil bat-
tery terminal of the starter relay. This normally open
switch prevents the starter relay from being ener-
gized when the ignition switch is turned to the Start
position, unless the clutch pedal is depressed. This
feature prevents starter motor operation while the
clutch disc and the flywheel are engaged. The starter
relay coil ground terminal is always grounded on
vehicles with a manual transmission.
If the vehicle is equipped with an automatic trans-
mission, battery voltage is supplied through the low-
amperage control circuit to the coil battery terminal
of the starter relay when the ignition switch is
turned to the Start position. The park/neutral posi-
tion switch is installed in series between the starter
relay coil ground terminal and ground. This normally
8F - 28 STARTINGDR

open switch prevents the starter relay from being
energized and the starter motor from operating
unless the automatic transmission gear selector is in
the Neutral or Park positions.
When the starter relay coil is energized, the nor-
mally open relay contacts close. The relay contacts
connect the relay common feed terminal to the relay
normally open terminal. The closed relay contacts
energize the starter solenoid coil windings.
The energized solenoid pull-in coil pulls in the sole-
noid plunger. The solenoid plunger pulls the shift
lever in the starter motor. This engages the starter
overrunning clutch and pinion gear with the starter
ring gear.
As the solenoid plunger reaches the end of its
travel, the solenoid contact disc completes the high-
amperage starter feed circuit and energizes the sole-
noid plunger hold-in coil. Current now flows between
the solenoid battery terminal and the starter motor,
energizing the starter.
Once the engine starts, the overrunning clutch pro-
tects the starter motor from damage by allowing thestarter pinion gear to spin faster than the pinion
shaft. When the ignition switch is released to the On
position, the starter relay coil is de-energized. This
causes the relay contacts to open. When the relay
contacts open, the starter solenoid plunger hold-in
coil is de-energized.
When the solenoid plunger hold-in coil is de-ener-
gized, the solenoid plunger return spring returns the
plunger to its relaxed position. This causes the con-
tact disc to open the starter feed circuit, and the shift
lever to disengage the overrunning clutch and pinion
gear from the starter ring gear.
DIAGNOSIS AND TESTING - STARTING
SYSTEM
The battery, starting, and charging systems oper-
ate in conjunction with one another, and must be
tested as a complete system. For correct starting/
charging system operation, all of the components
involved in these 3 systems must perform within
specifications.
Starting System Diagnosis
CONDITION POSSIBLE CAUSE CORRECTION
STARTER FAILS TO
OPERATE.1. Battery discharged or
faulty.1. Refer to Battery. Charge or replace battery, if required.
2. Starting circuit wiring
faulty.2. Refer to 8, Wiring Diagrams. Test and repair starter
feed and/or control circuits, if required.
3. Starter relay faulty. 3. Refer to Starter Relay in Diagnosis and Testing.
Replace starter relay if required.
4. Ignition switch faulty. 4. Refer to Ignition Switch and Key Lock Cylinder.
Replace ignition switch if required.
5. Clutch pedal position
switch faulty.5. Refer to Clutch Pedal Position Switch.
6. Park/Neutral position
switch faulty or
misadjusted.6. Refer to Park/Neutral Position Switch. Replace
park/neutral position switch if required.
7. Starter solenoid faulty. 7. Refer to Starter Motor. Replace starter motor assembly
if required.
8. Starter motor faulty. 8. If all other starting system components and circuits test
OK, replace starter motor.
STARTER ENGAGES,
FAILS TO TURN
ENGINE.1. Battery discharged or
faulty.1. Refer to Battery. Charge or replace battery if required.
2. Starting circuit wiring
faulty.2. Refer to 8, Wiring Diagrams. Test and repair starter
feed and/or control circuits if required.
3. Starter motor faulty. 3. If all other starting system components and circuits test
OK, replace starter motor assembly.
4. Engine seized. 4. Refer to Engine Diagnosis in the Diagnosis and Testing
section of 9, Engine.
DRSTARTING 8F - 29
STARTING (Continued)

reads from ª8º to ª18º volts. An International Control
and Display Symbol icon for ªBattery Charging Con-
ditionº is located on the cluster overlay, directly
below the right end of the gauge scale. The voltage
gauge graphics are black against a white field except
for a single red graduation at each end of the gauge
scale, making them clearly visible within the instru-
ment cluster in daylight. When illuminated from
behind by the panel lamps dimmer controlled cluster
illumination lighting with the exterior lamps turned
On, the black graphics appear blue and the red
graphics still appear red. The orange gauge needle is
internally illuminated. Gauge illumination is pro-
vided by replaceable incandescent bulb and bulb
holder units located on the instrument cluster elec-
tronic circuit board. The voltage gauge is serviced as
a unit with the instrument cluster.
OPERATION
The voltage gauge gives an indication to the vehi-
cle operator of the electrical system voltage. This
gauge is controlled by the instrument cluster circuit
board based upon cluster programming and elec-
tronic messages received by the cluster from the
Powertrain Control Module (PCM) on vehicles
equipped with a gasoline engine, or from the Engine
Control Module (ECM) on vehicles equipped with a
diesel engine over the Programmable Communica-
tions Interface (PCI) data bus. The voltage gauge is
an air core magnetic unit that receives battery cur-
rent on the instrument cluster electronic circuit
board through the fused ignition switch output (run-
start) circuit whenever the ignition switch is in the
On or Start positions. The cluster is programmed to
move the gauge needle back to the left end of the
scale after the ignition switch is turned to the Off
position. The instrument cluster circuitry controls
the gauge needle position and provides the following
features:
²System Voltage Message- Each time the clus-
ter receives a system voltage message from the PCM
or ECM indicating the system voltage is between
about 9.5 volts and about 15 volts, the gauge needle
is moved to the relative voltage position on the gauge
scale.
²System Voltage Low (Charge Fail) Message
- Each time the cluster receives three consecutive
messages from the PCM or ECM indicating the elec-
trical system voltage is less than about 9 volts
(charge fail condition), the gauge needle is moved to
the graduation on the far left end of the gauge scale
and the check gauges indicator is illuminated. The
gauge needle remains at the far left end of the gauge
scale and the check gauges indicator remains illumi-
nated until the cluster receives a single message
from the PCM or ECM indicating the electrical sys-tem voltage is greater than about 9.5 volts (but less
than about 15.5 volts), or until the ignition switch is
turned to the Off position, whichever occurs first. On
vehicles equipped with the optional diesel engine, the
ECM is programmed to restrict the voltage gauge
needle to a position above the graduation on the far
left end of the gauge scale and suppress the check
engine indicator operation until after the engine
intake manifold air heater has completed a pre-heat
or post-heat cycle.
²System Voltage High Message- Each time
the cluster receives three consecutive messages from
the PCM or ECM indicating the electrical system
voltage is greater than about 15.5 volts, the gauge
needle is moved to the graduation on the far right
end of the gauge scale and the check gauges indica-
tor is illuminated. The gauge needle remains at the
right end of the gauge scale and the check gauges
indicator remains illuminated until the cluster
receives a message from the PCM or ECM indicating
the electrical system voltage is less than about 15.0
volts (but greater than about 9.5 volts), or until the
ignition switch is turned to the Off position, which-
ever occurs first.
²Communication Error- If the cluster fails to
receive a system voltage message, it will hold the
gauge needle at the last indication for about five sec-
onds or until the ignition switch is turned to the Off
position, whichever occurs first. After five seconds,
the cluster will move the gauge needle to the far left
end of the gauge scale.
²Actuator Test- Each time the cluster is put
through the actuator test, the voltage gauge needle
will be swept to several calibration points on the
gauge scale in a prescribed sequence in order to con-
firm the functionality of the gauge and the cluster
control circuitry.
On vehicles with a gasoline engine, the PCM con-
tinually monitors the system voltage to control the
generator output. On vehicles with a diesel engine,
the ECM continually monitors the system voltage to
control the generator output. The PCM or ECM then
sends the proper system voltage messages to the
instrument cluster. For further diagnosis of the volt-
age gauge or the instrument cluster circuitry that
controls the gauge, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-
ING). If the instrument cluster turns on the check
gauges indicator due to a charge fail or voltage high
condition, it may indicate that the charging system
requires service. For proper diagnosis of the charging
system, the PCM, the ECM, the PCI data bus, or the
electronic message inputs to the instrument cluster
that control the voltage gauge, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
DRINSTRUMENT CLUSTER 8J - 41
VOLTAGE GAUGE (Continued)