The alternator is no different than the generator except that it does not have an external cutout. One wire will go from the alternator to the light switch to power the lights and the other will go to the junction box on the dash and through the ammeter to the foot starter switch or the add on fuse near the starter switch if you have one. The generator, or alternator, supplies power to the lights directly and to the battery for charging through the ammeter. When the engine is not running the battery will supply power to the lights through the ammeter, showing a discharge current.
Hope this helps. I suggest you get a wiring diagram from one of the books available or online.