Originally Posted by
Psy Guy
On my old bike running a negative/neutral wire from the rear light back to the generator wasn't necessary because I could ground the light to the frame and it'd still work. Not sure if that will work if your setup but it could reduce the number of wires. It might reguire that you ground the neutral side of the battery to the bike frame. I think thats how cars are wired, and why all the neutral wires don't go back to the alternator or battery.
Nope, it's an aluminum frame. Plus I have the rear light switched with the headlight, so I have 3 wires going to the back.
I am using a very similar setup, and using the aluminum frame for a ground works fine--just make sure you have a good connection to bare metal. I'm now using 2 grounds from the battery, in case one breaks (had that happen, lost all my lights till I figured it out).
Here is an older post of my system at that time (
http://www.bikeforums.net/showpost.p...postcount=1739 ). I still use a similar system: headlight is a MR-16 3 LED bulb, LED beehive rear lights, and 5 Ahr SLA battery. Not the fanciest system, but it works day in, day out for years.