Originally Posted by
obrentharris
It looks like your rear light has only one wire going to it. That would be the hot wire. But it also needs a ground. I would guess that it is designed to ground through the frame. That may be what the little threaded hole on the clamp is for, to accommodate a pointed screw that would pierce through the paint to the metal stay to provide a ground. With the cloth tape and paint blocking the ground path the light won't work.
You will need to find a way to ground the light. An easy solution would be to run a wire from the mounting clamp of the light to the mounting screw of the generator. You can test my theory by temporarily attaching a wire between those two points and then testing the light.
Brent
ah-ha! there was in fact a ground wire attached before i started messing with it, it was poorly soldered to the light's mount, i think... i didn't look carefully before removing it.
your instructions make sense though - i'll tinker with it tonight and hopefully it will work. i looked at the bulb and it didn't appear to be burnt out.