Alternator and Regulator Circuit Troubleshooting

Alternator and Regulator Circuit Troubleshooting

Special Tools Required

- Alternator, Regulator, Battery & Starter tester OTC3131
Available through the Honda Tool and Equipment Program.

1. Make sure the battery connections are good and the battery is sufficiently charged.

2. Connect the alternator, regulator, battery & starter tester (OTC3131) to the battery as shown.






3. Start the engine. Hold the engine speed at 3,000 rpm with no load in neutral until the radiator fan comes on, then let it idle.

4. Do the CHARGING SYSTEM TEST.

Does the display indicate the voltage is within 13.5-15.1 V the amperage is 87.5 A or more?
YES - Go to step 5.

NO - If the voltage is less than 13.5 V, go to alternator control circuit troubleshooting. Alternator Control Circuit Troubleshooting If the voltage is over 15.1 V and amperage is less than 87.5 A, replace the alternator Removal and Replacement or repair the alternator. Overhaul


5. Check the diode condition on the display.

Does the display indicate GOOD?
YES - The diode is OK. Troubleshooting is complete.

NO - If the display indicates BAD, replace the alternator Removal and Replacement or repair the alternator, Overhaul then retest.
NOTE: If the display indicates N/A, the diode pattern could not be diagnosed. Repeat the test again.