The ground is solid and right on an unpainted surface on the frame. I can't imagine it lost connection I have been running it without problems since last summer.
Have you checked your fuses in the fusebox? Maybe the voltage regulator? I dunno, I'm just throwing crap against the wall and seeing if anything sticks.
The kit has an inline fuse and that one looked fine. If anything was to blow in that area the in line fuse would have went first, at least thats what my knowledge is telling me. Might just be cause it was a crappy ballast but since I have had this problem with a couple different brand of kits I can't be too sure.
Right, I'm just thinking that if there is a fuse in the fusebox that came loose or burned out from an unrelated cause, it could possibly cause the issue with your headlight. :don'tknow: