brake lights

So I'll be posting pics soon of my build. All I have left is to buy and install my seat and buy and install my taillight. My question is anyone know what I need to do to make the brake light harness work with an aftermarket light that has 2 or 3 wires? Since the harness has 8 wires,2 blue 3...

Hey guys been here for a year, but still in the newbie range (I'm wrenchy but could use suggestions for a book that breaks down motorcycle mechanics and maintenance?). My '83 XS400 has a few issues I need to look into, but most pressing right now is electrical. I've recently noticed that...