Hummer H3. Manual — part 1134

This vehicle has a 12-volt positive, negative ground electrical system. Do not try to jump start a
vehicle, if you are unsure of the other vehicle's positive voltage or ground position. The booster
battery and the discharged battery should be treated carefully when using jumper cables.

1. Position the vehicle with the booster battery so that the jumper cables will comfortably

reach the battery of the other vehicle.

Do not let the 2 vehicles touch.

Make sure that the jumper cables do not have loose clamps or missing insulation.

2. Perform the following steps on both vehicles:

1. Place the automatic transmission in PARK.

2. Block the wheels.

3. Set the parking brake.

4. Turn off all electrical loads that are not needed. Leave the hazard flashers ON.

5. Turn OFF the ignition switch.

the following guidelines:

Always shield your eyes.

Avoid leaning over the battery whenever possible.

Do not expose the battery to open flames or sparks.

Do not allow battery acid to contact the eyes or the skin.

Flush any contacted areas with water immediately
and thoroughly.

Get medical help.

NOTE:

This vehicle has a 12 volt, negative ground electrical system. Make
sure the vehicle or equipment being used to jump start the engine
is also 12 volt, negative ground. Use of any other type of system will
damage the vehicle's electrical components.

2007 Hummer H3

2007 ENGINE Engine Electrical - H3

Fig. 10: Identifying Proper Jumper Cable Connection
Courtesy of GENERAL MOTORS CORP.

IMPORTANT: Some vehicles have a battery remote positive stud. ALWAYS

use the battery remote positive stud in order to give or to
receive a jump start. Consult the vehicle's owner's manual

2007 Hummer H3

2007 ENGINE Engine Electrical - H3

3. Attach the end of one jumper cable to the positive terminal of the discharged battery.

4. Attach the other end of the first cable to the positive terminal of the booster battery.

5. Attach one end of the remaining jumper cable to the negative terminal of the booster

battery.

6. Make the final connection of the negative jumper cable to the block or suitable bracket

connected directly to the block, away from the battery.

7. Start the engine of the vehicle that is providing the jump start and turn off all electrical

accessories. Raise the engine RPM to approximately 1,500 RPM.

8. Crank the engine of the vehicle with the weak battery.

If the engine does not crank or cranks too slowly, perform the following steps:

1. Turn the ignition OFF.

2. Allow the booster vehicle engine to run at approximately 1,500 RPM for 5 minutes.

3. Attempt to start the engine of the vehicle with the discharged battery.

9. Reverse the steps exactly when removing the jumper cables. The negative battery cable must

first be disconnected from the engine that was jump started.

CHARGING SYSTEM TEST

Charging System Test

for proper connections.

NOTE:

Do not connect the negative charger lead to the housings of
other vehicle electrical accessories or equipment. The action
of the battery charger may damage such equipment.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic
System Check - Vehicle?

-

Go to Step

2

Go to Diagnostic
System Check -
Vehicle

2

Did you perform the Battery
Inspection Test?

IMPORTANT:

The battery must be above a 70
percent state of charge.

-

Go to Step

3

Go to Battery
Inspection/Test
(Non-HP2)

2007 Hummer H3

2007 ENGINE Engine Electrical - H3

3

1. Install a scan tool.

2. Start the engine.

3. With a scan tool, command

the GEN-L Terminal OFF
and ON.

4. Observe the Ignition 1

Signal parameter.

Does the voltage change with
each command?

-

Go to Step

4

Go to Step 8

4

1. Turn ON the following

accessories:

Headlights-high beams

A/C on Max

Blower fan-ON high

Heated seats, if
equipped

2. With a scan tool, observe

the ignition 1 signal
parameter in the engine data
list.

3. Increase engine speed to

2,500 RPM.

Is the voltage within the specified
value?

12-15.5 V

Go to Step

5

Go to Step 6

1. Turn OFF all accessories.

2. Turn OFF the ignition.

CAUTION:

Make sure that the load is
completely turned off before
connecting or disconnecting
a carbon pile load tester to
the battery. Otherwise,
sparking could ignite battery
gasses which are extremely
flammable and may explode

2007 Hummer H3

2007 ENGINE Engine Electrical - H3