Introduction - Dodge ram truck 3500 1996 Service Manual

BR STARTING SYSTEMS 81 - 1
S T A R T I N G
SYSTEMS
CONTENTS
page
GENERAL INFORMATION
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . 1
OVERVIEW 1
DESCRIPTION AND OPERATION
STARTER RELAY 2
STARTER 2
STARTING SYSTEM 1
DIAGNOSIS AND TESTING
COLD CRANKING TEST 4
page
CONTROL CIRCUIT TESTS 6
FEED CIRCUIT TESTS 4
STARTING SYSTEM 2
. . IE10VAL AND INSTALLATION
STARTER RELAY 10
STARTER 8
SPECIFICATIONS
STARTING SYSTEM 10
GENERAL I N F O R M A T I O N
OVERVIEW
The battery, starting, and charging systems oper­
ate with one another, and must be tested as a com­
plete system. In order for the vehicle to start and
charge properly, all of the components involved in
these systems must perform within specifications.
Group 8A covers the battery, Group 8B covers the
starting system, and Group 8C covers the charging
system. Refer to Group 8W - Wiring Diagrams for
complete circuit descriptions and diagrams. We have
separated these systems to make i t easier to locate
the information you are seeking within this Service
Manual. However, when attempting to diagnose any
of these systems, it is important that you keep their
interdependency in mind.
The diagnostic procedures used in these groups
include the most basic conventional diagnostic meth­
ods to the more sophisticated On-Board Diagnostics
(OBD) built into the Powertrain Control Module
(PCM). Use of a induction milliampere ammeter, volt/
ohmmeter, battery charger, carbon pile rheostat (load
tester), and 12-volt test lamp may be required.
All OBD-sensed systems are monitored by the
PCM. Each monitored circuit is assigned a Diagnos­
tic Trouble Code (DTC). The PCM will store a DTC In
electronic memory for any failure it detects. See the
On-Board Diagnostics Test in Group 80 - Charging
System for more information.
INTRODUCTION
The starting system consists of:
• Battery
• Starter relay
• Starter with an integral solenoid
• Ignition switch
© Clutch pedal position switch (manual transmission)
• Park/neutral position switch (automatic trans­
mission)
• Wiring harness and connections.
This group covers diagnosis of the complete start­
ing system, except the battery. However, this group
only covers service procedures for the starter and
starter relay. Service procedures for other starting
system components can be located as follows:
• Battery - refer to Group 8A - Battery for the
diagnostic and service procedures
• Ignition switch - refer to Group 8D - Ignition
Systems for the service procedures
• Clutch pedal position switch - refer to Group 6 -
Clutch for the service procedures
• Park/neutral position switch - refer to Group 21
- Transmission for the service procedures
• Wiring harness and connections - refer to Group
8W - Wiring Diagrams for the service procedures.
D E S C R I P T I O N A N D O P E R A T I O N
STARTING SYSTEM
The starting system components form two separate
circuits. A high-amperage feed circuit that feeds the
starter between 150 and 350 amperes (700 amperes -
diesel engine), and a low-amperage control circuit
that operates on less than 20 amperes.
If the vehicle is equipped with an automatic transmis­
sion, battery voltage is supplied through the low-amper­
age control circuit to the coil battery terminal of the
starter relay when the ignition switch is turned to the
Start position. If the vehicle is equipped with a manual
transmission, it has a clutch pedal position switch. The
clutch pedal position switch is connected in series
between the ignition switch and the coil battery termi­
nal of the starter relay. This normally open switch