An alternator tester is provided for testing an alternator of a vehicle
while the alternator is coupled to the vehicle. A sensor is configured to
couple to the vehicle and sense a signal related to operation of the
alternator. A memory contains data related to operator instructions for
performing an alternator tester of a function of vehicle type. A
processor configured to provide an output indication of alternator
condition based upon the sensed signal. An extra load or connection can
be provided for coupling to the electrical system.