An alternator (AC generator), which is to be attached to an engine mounted to a vehicle, comprises an output terminal to which one end of a cable for supplying a battery with power generated by the alternator is coupled. The battery is mounted on the vehicle. The alternator further comprises an insulator, a guide, and a direction setting member. The insulator, made from an electric insulative material, is for protecting the output terminal. The guide guides the cable along a desired direction from the output terminal. The direction setting member enables the guide to selectively set a direction among a plurality of predetermined directions along which the cable is allowed to be guided.