I don't know anything to speak of about electronics, but like everyone else who sometimes rides at night, I want to be seen and it would also be nice to see where I'm going. I tried a 12 volt generator a couple of years ago and riding at speed would continually burn out the bulbs. I had a 6 volt generator and the same thing happened. No doubt there's a way around that, but that's for somebody else to fiddle with, somebody smarter than me.
I tried hooking up the white wire to run both a tail light 6 v. bulb and headlight 6 v. bulb and it killed the engine. Then I ordered some LED lights from
eBay Store - Empat Manufacturing: Single Chrome Mount, Single 12 Volt 5mm, Red
...which ran seven bucks for ten LEDs. I bought 20 of them and wired as many as would fit in the headlight, five or so in the tail light and another five in the brake light. No problem with killing the engine or weak starts and my lights come on automatically with the engine running. You could wire in a switch easily enough. The light is flickering and is OK with me since for the most part I want to be seen. I don't have much occasion to ride in the dead of night, needing to light the road ahead of me. It does light enough to see where I'm going, but I live out in the forest and it would be different in a city situation with lots of traffic, competing lights, etc. It has proved to be adequate for me and so far no problems. If this is going to wreck something, I'd appreciate a heads up. On another bike I run all of those lights plus a 12 volt fender light from a Kawasaki motorcycle. I don't know why it works, but it does. A while back I was in the Target store and saw they had a string of 18 white christmas lights which were battery powered, and came with a little battery box to hold four AA batteries... which works out to 6 volts. I thought, "why not?". since the price was right at $7.99. I bought a couple sets and got experimenting. The leds are smaller than the others I ordered, but I think seem just as bright. In one headlight I fitted eighteen of the xmas tree lights in there, with another five or six each of the other leds in the tail light and brake light. They work fine and have not killed the engine or caused starting problems. The eighteen christmas tree lights are brighter than ten of the other, so Target is a better deal, especially with no shipping expenses. I wired up my other American the same way and it is entirely adequate for my needs. I have thought about also wiring up the little battery box the Christmas lights came with. It has a switch on it and could fit under the seat. That way if my engine quit I could switch on the batteries and still be seen along the side of the road as I peddle or push my bike home. Doing over old cruiser lights this way is kind of fun... gutting out the old light fixture and cramming all the wiring inside the headlight, so that just a single power wire and ground exit the unit. The wires are smaller in the Christmas tree lights, thus a little harder to work with, but take up less room. LED lights have a positive and a negative polarity. Get the wires reversed and they won't light up. On the bigger LRDs the wires are red and black, so easy to tell what is what. With the xms lights all is green, so you have to check. As I said this "system" is cheap, easy enough to do and runs entirely off the engine. I'm sure there are better setups, but this works for me.