With no battery in the circuit to act as a buffer, the alternator can put out up to 150 volts, depending on engine rpm. When ...

Instead, use a common voltmeter and the following test procedure ... If there's no arc, the alternator has an open Field circuit or worn-out brushes. Fix or replace as needed.

The alternator ... simulate a short circuit to determine faultiness, as it could put you or other people helping you at risk. Also, never try to check out the generator’s performance when it’s ...