[Chris99GMC]

Its because its magnetic that it makes power. When you move a magnet around a wire, it induces a current in the wire. When you put a whole bunch of magnets in there and a whole bunch of wire and spin it really fast, it makes lots of current, or at least enough for a truck.

Yes seriously.... but If someone doesn't know how a coil works, they don't know Jack about how a car works.

Pretty good explaining on the alternator. It's all about the Recifers(little diode that switches back and forth and back and forth to make one continuous current flow)