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8.2
Charging System Test
All late-model vehicles need a constant supply of power to run their
electronic components, such as computers, daytime running lights
and stereo systems. Most 12-volt charging systems produce more
than 12 volts, some as high as 14.5 volts of DC power. Many
electronic ignitions will not operate efficiently using only 12 volts,
and the engine will under-perform, reducing horsepower and gas
mileage. To ensure the battery will remain charged to start the
vehicle and power the accessories while it's running, test the integrity
of the 12-volt charging system periodically.
Before starting the test, inspect the alternator drive belt. A belt that is
glazed or worn, or lacks the proper tension, will prevent the engine
from achieving the RPM levels needed for the test.
CHARGING SYSTEM TEST PROCEDURE
There are two ways to do this test.
A.
Connecting to DLC with OBDII connector.
B.
Connecting to battery with probes.
Follow the steps to complete the test:
1.
Turn off all of the vehicle's electrical accessories.
2.
Connect the tool to vehicle’s DLC with OBDII connector, or
contact the scan tool probes to the battery: red to the positive (+)
terminal, black to the negative (-) terminal.
3.
Turn on the scan tool and wait for Main Screen to appear.
(Figure 3.1)
4.
Use the
UP
/
DOWN
scroll button to select
START TEST
from
main screen. (Figure 3.1) Then select
CHARGE TEST
in the
submenu. The screen will show as below.
