Amperage Output Test
NOTE:
Ammeter with inductive pick-up clamp-type test lead is recommended. Perform test soon after starting engine, as charging amperage will drop quickly.
- Disconnect negative battery cable. Disconnect alternator output wire from alternator terminal "B". See Fig 1 . Connect ammeter in series between terminal "B" and disconnected output wire. Connect voltmeter between terminal "B" and ground. Reconnect negative battery cable.
- Voltmeter should read battery voltage. If voltmeter reads zero volts, check for an open in wire between alternator "B" terminal and positive battery terminal, a blown fusible link or a poor ground connection.
- Turn on all electrical accessories. Start engine and accelerate to 2500 RPM. Read maximum amps output. If alternator amps output is within 10 percent of rated current output, alternator is functioning properly. See ALTERNATOR SPECIFICATIONS table.