I do believe it's part of the main harness. I have a feeling the connector hiding between 17 & 40 in the picture may be it.
http://houseofmotorcycles.bikebandit.com/triumph-motorcycle-speed-master/o/m6898
I'm not far behind you in breaking mine, the way they have it all crammed into such a small space in the battery box area.
It shouldn't be too difficult to make a new one and bypass the old one if necessary. I'm strongly considering this if only to make the cable more movable without fighting the constraints of the harness each time I need to pull the battery.
