I'm working on the tail ligt assembly for a 08 SG. Can someone tell me what color wire is the hot one for the runnning / brake light?

 

Bump Bump

 

MSOB, the run light and brake light are on two different wires. Typically, the run light wire is blue; the brake light wire is red/yellow stripe. Consult the Service Manual for your bike to be sure. And if you don't have a Service Manual, do yourself a favor and buy one.

Also, you can use a test light to identify the wires. Put the ignition "on" and the run light will have power; put the ignition in "acc" and that wire won't have power. Operate the brake (helps to have really long arms or piece of wood to press pedal) with the ignition in either position and the brake wire will light your test light.

Could luck with your project. And seriously, buy the Service Manual so you won't go through the aggravation of waiting for help on the internet in the middle of a project.