Stop in for a cup of coffee
Mike tell him to 1st check the battery. The rest of the tests are require working with a good battery that is charged.
Simplest at home load test is measure the battery voltage when starting. Under 9.5 V and the battery needs a charge or replacement.
Next, he should observe the ammeter with the engine running. Is the battery getting charged at fast idle? How about slow idle? Once its charged (centered) turn on the lights and see if the battery is supplying power to the lights (discharge). If it is, then he can investigate the charging system - could be anything from idling too slow to blown diode.
Mike tell him to 1st check the battery. The rest of the tests are require working with a good battery that is charged.
Simplest at home load test is measure the battery voltage when starting. Under 9.5 V and the battery needs a charge or replacement.
Next, he should observe the ammeter with the engine running. Is the battery getting charged at fast idle? How about slow idle? Once its charged (centered) turn on the lights and see if the battery is supplying power to the lights (discharge). If it is, then he can investigate the charging system - could be anything from idling too slow to blown diode.