Reader Electrical Gremlins

Mike writes in with an electrical question:

I recently purchased a not-quite-running Yamaha R5B, and first off I'd like to thank you for compounding all the information you have! your site has been a major help while I'm working on the bike, and for just learning all I can about it since it is my first motorcycle. I have two questions for you, the first is that the bike didn't come with front turn signals installed, but luckily I was able to get ahold of the correct pair from my uncle. Unfortunately my wiring knowledge is limited to replacing wires where the old ones were, but with your site's help I was able to hook up the brown and green wire clusters to their respective bulbs, but I am not sure where/how to ground them. Both have the eye terminal wires coming off of the bolts on the signals, but I am unsure of where exactly to plug them into. The second is that the bike has a short somewhere and keeps blowing the main fuse off the positive battery terminal. All lights/signals/horn work as they should it seems (except the ones I haven't grounded/hooked up). The bike starts, will run for a minute or so before either dying of a spent battery or the main fuse going. I started checking for continuity, and sure enough there was continuity between the positive and negative battery hook-ups with the key on, started following it back and it lead me to the red wire entering the rectifier. I'm not sure where to go/what to do from there, or even if there is supposed to be continuity through there! Do you have any insight/ideas for tracing the fault? Thanks again for the site, and any thoughts you may have!

Any feedback or suggestions greatly appreciated.