Re: Light powered by engine
I have a 3 AAA cell LED flashlight grounded to the frame and (+) wired to the white. While idling, the light is dim & flickering, but definitely visible. As I accelerate, the light gets brighter with the engine speed and seems to get as bright as it ever did with batteries.
Simple to do, but I don't know that I would ever wire a lesser powered light to it - LED is perfect because it's polarized and doesn't allow harmful polarity to pass. I attempted to connect an identical LED flashlight as a tail-light, but it caused neither light to function, so I guess they must have grounded one another out or reduced voltage to not function - the engine never missed a lick, either way.