Hummer H2. Manual — part 1113

Fig. 66: View Of Battery Danger Label
Courtesy of GENERAL MOTORS CORP.

The maintenance free battery is standard. There are no vent plugs in the cover. The battery is completely sealed
except for 2 small vent holes in the side. These vent holes allow the small amount of gas that is produced in the
battery to escape.

The battery has 3 functions as a major source of energy:

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Engine cranking

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Voltage stabilizer

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Alternate source of energy with generator overload

The battery specification label, example below, contains information about the following:

CAUTION: Batteries produce explosive gases, contain corrosive acid, and supply

levels of electrical current high enough to cause burns. Therefore, to
reduce the risk of personal injury when working near a battery:

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Always shield your eyes and avoid leaning over the battery whenever
possible.

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Do not expose the battery to open flames or sparks.

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Do not allow the battery electrolyte to contact the eyes or the skin.
Flush immediately and thoroughly any contacted areas with water
and get medical help.

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Follow each step of the jump starting procedure in order.

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Treat both the booster and the discharged batteries carefully when
using the jumper cables.

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2

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The test ratings

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The original equipment catalog number

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The recommended replacement model number

Fig. 67: Battery Specification Label
Courtesy of GENERAL MOTORS CORP.

Battery Ratings

A battery has 2 ratings:

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Reserve capacity

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Cold cranking amperage

When a battery is replaced use a battery with similar ratings. Refer to the battery specification label on the
original battery or refer to Battery Usage .

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2

Reserve Capacity

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.

CHARGING SYSTEM DESCRIPTION AND OPERATION

Generator

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

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The delta stator

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The rectifier bridge

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The rotor with slip rings and brushes

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A conventional pulley

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Dual internal fans

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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 30/44 denotes the
outside diameter of the stator laminations in millimeters, over 100 millimeters. The generators is rated at 145
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.

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:

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Radio noise control

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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

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2

be 90 percent and the off-time 10 percent.

Charging System Indicator

The IPC illuminates the charge indicator in the message center when the following occurs:

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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.

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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.

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

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The ignition is on, with the engine off.

STARTING SYSTEM DESCRIPTION AND OPERATION

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

2004 Hummer H2

2004 ELECTRICAL Engine Electrical - Hummer H2