Which is hot? wire with stripe?

I mounted my new signals (one wire) and wired them to the wire with the stripe. When I touch the black to the mounting bolt, the tail light dims and the fuse blows.

Last edited by Cowtipper; 12/02/2007 1:54 PM.
2002 Bandit 1200/ GSXR cams/ 1277 BB Kit/ Holeshot header and can/ 38mm flatslides/ a good head/lotsa hp/lotsa tq- lots of rear tires...