OK, your post make a lot of sense. thanks.

the shimano instructions say that you shouldn't touch the connectors, because there might be high voltage coming off of the hub. so, you're right, there is no regulator in the hub itself. all the regulators are in the lights, so that's why you want to have them in series. makes sense.

the wire from the lumotec lite is coax. i assumed that the inner wire is positive and the outer is ground. i am very sure (OK, check when i get home) that i put the outer wire to the ground position on the hub. the outer one is the one that the switch on the light is connected to.

hmmm....

so the more i think about it, i assumed that the outer wire should be ground...

but, if the power coming off of the hub is AC (which i just realized that is should be), then which wire is the grounding wire just has to be uniform.....

i'll go back and make continuity measurements on the light again, taking into account that there may be a couple of diodes in it.

thanks a lot!!

mark