Alternator and Regulator Circuit Troubleshooting

1.Be sure the battery connections are good, and that the battery is sufficiently charged.

2.Hook up the following equipment:

  • Ammeter, 0-400 A
  • Voltmeter, 0-20 V (accurate within 0.1 V)

 

3.Shift to Neutral, and start the engine. Hold the engine at 3,000 rpm (min-1) with no load until the radiator fan comes on, then let it idle.

4.Raise the engine speed to 2,000 rpm (min-1) and hold it there.

5.Turn the headlights (high beam) on, and measure voltage at the alternator terminal.

Is the voltage between 13.3 and 15.3 V?


YES - Go to 6.


NO - Replace the alternator or repair the alternator.n

6.Read the voltage at 13.5 V.

NOTE: Adjust the voltage by turn the blower motor, rear window defogger, brake lights and etc. on.

Is the amperage 60 A or more?


YES - Go to the Alternator Control Circuit Troubleshooting.n


NO - Replace the alternator or repair the alternator.n