Hummer H3. Manual — part 27

Reserve capacity is the amount of time in minutes it takes a fully charged battery, being
discharged at a constant rate of 25 amperes and a constant temperature of 27°C (80°F) to reach a
terminal voltage of 10.5 volts. Refer to Battery Usage for the reserve capacity rating of the
original equipment battery.

Cold Cranking Amperage

The cold cranking amperage is an indication of the ability of the battery to crank the engine at
cold temperatures. The cold cranking amperage rating is the minimum amperage the battery must
maintain for 30 seconds at -18°C (0°F) while maintaining at least 7.2 volts. Refer to Battery
Usage for the cold cranking amperage rating for this vehicle.

Auxiliary Battery

Auxiliary batteries are an available option on vehicles where many accessories can be utilized
such as TVs, radios, lights, computers, etc. The charging of these batteries is explained in
charging system description and operation. Also, the auxiliary battery is only for accessory use
and not part of the starting system.

CHARGING SYSTEM DESCRIPTION AND OPERATION

Generator

The AD-244 generator is non-repairable. They are electrically similar to earlier models. The
generator(s) feature the following major components:

The delta stator

The rectifier bridge

The rotor with slip rings and brushes

A conventional pulley

Dual internal fans

A voltage regulator

The pulley and the fan cool the slip ring and the frame.

The AD stands for Air-cooled Dual internal fan; the 2 is an electrical design designator; the 44
denotes the outside diameter of the stator laminations in millimeters, over 100 millimeters. The
generator is rated at 150 amperes.

The generator features permanently lubricated bearings. Service should only include the
tightening of mounting components. Otherwise, the generator is replaced as a complete unit.

2006 Hummer H3

2006 ENGINE Engine Electrical - H3

Regulator

The voltage regulator controls the field current of the rotor in order to limit system voltage. The
regulator switches the current on and off at a rate of 400 cycles per second in order to perform
the following functions:

Radio noise control

Obtain the correct average current needed for proper system voltage control

At high speeds, the on-time may be 10 percent with the off-time at 90 percent. At low speeds, the
on-time may be 90 percent and the off-time 10 percent.

Charging System Indicators

BATTERY

The IPC illuminates the battery indicator when the following occurs:

The PCM detects that the generator output is less than 11 volts or greater than 16 volts. The
IPC receives a class 2 message from the PCM requesting illumination.

The IPC determines that the system voltage is less than 11 volts or greater than 16 volts. The
IPC receives a class 2 message from the body control module (BCM) indicating the system
voltage.

The IPC performs the displays test at the start of each ignition cycle. The indicator
illuminates for approximately 3 seconds.

The ignition is on, with the engine off.

BATTERY NOT CHARGING

The IPC illuminates the battery not charging indicator in the driver information center when the
following occurs:

The PCM detects that the generator output is less than 11 volts or greater than 16 volts. The
IPC receives a class 2 message from the PCM requesting illumination.

The IPC determines that the system voltage is less than 11 volts or greater than 16 volts. The
IPC receives a class 2 message from the body control module (BCM) indicating the system
voltage.

STARTING SYSTEM DESCRIPTION AND OPERATION

The PG-260L is a non-repairable starter motor. It has pole pieces that are arranged around the

2006 Hummer H3

2006 ENGINE Engine Electrical - H3

armature within the starter housing. When the solenoid windings are energized, the pull-in
winding circuit is completed to ground through the starter motor. The hold-in winding circuit is
completed to ground through the solenoid. The windings work together magnetically to pull in
and hold in the plunger. The plunger moves the shift lever. This action causes the starter drive
assembly to rotate on the armature shaft spline as it engages with the flywheel ring gear on the
engine. At the same time, the plunger closes the solenoid switch contacts in the starter solenoid.
Full battery voltage is then applied directly to the starter motor and it cranks the engine.

As soon as the solenoid switch contacts close, current stops flowing thorough the pull-in winding
as battery voltage is now applied to both ends of the windings. The hold-in winding remains
energized; its magnetic field is strong enough to hold the plunger, shift lever, starter drive
assembly, and solenoid switch contacts in place to continue cranking the engine. When the engine
starts, the pinion gear overrun sprag protects the armature from excessive speed until the switch is
opened.

When the ignition switch is released from the CRANK position, voltage is removed from the
starter solenoid S terminal. Current flows from the motor contacts through both windings to
ground at the end of the hold-in winding. However, the direction of the current flow through the
pull-in winding is now in the opposite direction of the current flow when the winding was first
energized.

The magnetic fields of the pull-in and hold-in windings now oppose one another. This action of
the windings, along with the help of the return spring, cause the starter drive assembly to
disengage and the solenoid switch contacts to open simultaneously. As soon as the contacts open,
the starter motor is turned off.

SPECIAL TOOLS AND EQUIPMENT

SPECIAL TOOLS

Special Tools

Illustration

Tool Number/ Description

J 38758

Parasitic Draw Test Switch

2006 Hummer H3

2006 ENGINE Engine Electrical - H3

J 42000

Battery Tester

2006 Hummer H3

2006 ENGINE Engine Electrical - H3