I'm almost positive that cable is part of the wiring harness. Short of replacing the whole harness, I suppose you could splice a new wire if you need to, but try to avoid doing that!
I couldn't tell you why the bike won't start. Silly question, is it in neutral? If it's in gear with the kickstand down, it won't start. That's happened to me loads of times haha. But a loud clicking noise sounds like a starter issue. At least on a car it would be the solenoid not engaging. Check the battery connections too and be sure the battery has the right amount of charge. If it's low, the starter will try and fail to start the bike. Good luck!
Edit: Just looked back at the picture again. That cable is fine. Unscrew it from the broken piece. The new part comes with a new screw.
Edit 2: My bad about the protective plate. Forgot you have fairing over there. The Speed Four doesn't have fairing so it has a plate instead. You're good!
Last edited by Bugler; 11-13-2012 at 09:06 AM.