Homemade lighting troubles.
Recently I converted two all metal bicycle lights to run on batteries. Normally these run on generator power, but I don't quite like tire dynamos. For extra light I used two of them. Bought one of those 6v D cell battery packs from radioshack and after a little soldering it worked great, for a little while at least. See, when the lights are not mounted, they work when separated. When you touch them together they ground together and the lights go out. Went ahead and mounted them anyway [both fork mounted lights] and they ground when you turn them on. Just as a test I removed one light and it worked fine. Would a plastic mount fix this problem? Anything else?