Ok, I gotcha now. My coil is a bit different from yours, so I'm giving it my best guess. Where you have it hooked up right now is on the positive terminal of the coil. You don't want to hook up your signal wire to that. The wire that appears to be "hardwired" looks to be your negative/ground wire for the coil. Follow the wire from the coil to where it mounts next to that white box you described earlier. That location is where you want to attach your signal wire. Try that out and let us know if it worked.