You might be saying to yourself… “Hey this looks just like the generator wiring diagram!” …. and that would be because it basically is. The only difference is that there is an alternator instead of a generator and that the regulator is a regulator/rectifier because the alternator puts out ac current that the bike can’t use. Therefore the ac current out of the stator needs to be rectified into dc current.
Notice that there is no ground connection to the stator itself. If the stator has a path to ground it is bad.
Also, while this is typically associated with Big Twin Shovelheads and Evo’s, it would also work for later model Sportsters with alternators. 1984 and up.
You’ll also notice that the kick start only diagram is the same minus the electric start circuit. On kick only you can simply run your ground from the battery to the frame. All you need for that ground is a 14 gauge wire.
Did I not say it was simple?