What is alternator output in amps?

The alternator (or generator) of a vehicle is the unit that converts the mechanical energy from the drive-belt into electricity. Amperage (amps) are the output level of the alternator. Alternator part number, as well as output amps are specific to each vehicle.

Another Answer

Your question is a little like asking, "How long is a length of string?"! The rated output current of an alternator depends on its rated output power rating and its rated terminal voltage. The rated output power can vary tremendously, according to the physical size of the machine.