Jeep 1996 Grand Cherokee Service Manual - Starting Systems
STARTING SYSTEMS
CONTENTS
page
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
CONTROL CIRCUIT TESTS . . . . . . . . . . . . . . . . . 5
FEED CIRCUIT TESTS . . . . . . . . . . . . . . . . . . . . . 4
STARTING SYSTEM . . . . . . . . . . . . . . . . . . . . . . 2
REMOVAL AND INSTALLATION
STARTER RELAY . . . . . . . . . . . . . . . . . . . . . . . . 8
STARTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
SPECIFICATIONS
STARTING SYSTEM . . . . . . . . . . . . . . . . . . . . . . 8
GENERAL INFORMATION
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 it 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 8C - Charging
System for more information.
INTRODUCTION
The starting system consists of:
• Battery
• Starter relay
• Starter with an integral solenoid
• Ignition switch
• 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
• 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.
DESCRIPTION AND OPERATION
STARTING SYSTEM
The starting system components form two separate cir-
cuits. A high-amperage feed circuit that feeds the starter
between 150 and 350 amperes, and a low-amperage con-
trol circuit that operates on less than 20 amperes.
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. The park/neutral position switch
is installed in series between the starter relay coil
ground terminal and ground. This normally open
switch closes only with the automatic transmission
gear selector in the Neutral or Park positions.
With the starter relay coil now 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.
ZJ
STARTING SYSTEMS
8B - 1