Charging System Test

CAUTION: Safety glasses should be worn. Rings, watches and all other hand jewelry should be removed.

NOTE: Test is performed using a Starting And Charging System Tester (SA9154Z-A).

NOTE: If a fusible link is blown, do not just replace it. The most probable cause of a blown link is an internal generator failure. Verify that there is no external arcing or shorting of fusible link with other wires and/or components. If no problems are found, replace the generator.

Verify the fusible link between the starter and generator is good.
Verify the connections are tightened to specification and clean. The charging system light functional test will verify the link is okay.
Turn the system tester ON.
Connect large Red tester cable to the battery positive.
Connect large Black tester cable to the battery negative.
Place Gray inductive current pick-up around the battery positive cable. Make sure that arrow on the Gray inductive current pick-up is pointing toward the starter motor solenoid.

NOTE: Verify the inductive current pickup is completely closed around the cable.

Place the Gray inductive current pick-up around the battery positive cable between the battery positive terminal and the starter motor solenoid connection. The easiest place to connect the inductive pick-up is next to the brake master cylinder. The battery positive cable runs under the master cylinder and is covered by a protective wire conduit. This conduit does not need to be removed for this test. On vehicles equipped with ABS brakes, the pick-up can be placed between the ABS master cylinder and starter motor.

NOTE: A flat battery will adversely affect the charging system results. Perform battery test before performing the charging system test.

Perform the battery load test to verify a good battery.
Start engine and turn all accessories OFF.
Follow the charging and starting system tester prompts.
Using the tester, press the CHARGING SYSTEM TEST. The display should show the correct number of cylinders. To change the number of cylinders, simply press that number on the keypad. The tester will display the voltage and current output of the generator. The voltage output, with a good battery, should be 13.0-15.5 volts.

NOTE: The output of the generator is dependent on the demand (load), temperature, and RPM of the generator.

For the generator output current, see GENERATOR OUTPUT TEST .
Ignore the diode pattern test if the generator does not pass the voltage and current tests. If the output current is less than 20 amps, verify the charge warning telltale operation on I/P cluster. If the output current is greater than 20 amps, but less than the specified minimum current, ensure that the Gray amp probe is properly installed and the generator belt is in good condition. If both passes the test, replace generator.

GENERATOR OUTPUT TEST

Generator Inlet Air Temperature	Engine RPM	Output (Amps)
81°F (27 °C)	650	26
875		60
1000		67
1500		77
2000		85
200 °F (93 °C)	650	28
875		48
1000		53
1500		64
2000		72