The problem as several have pointed out is that the battery may be the problem. We went thru this about 10 years or so ago and some of us took to heart what was being suggested so we went for the fix hoping these guys were right. Back than this Dogs were ridden long distances and Raywood was one of them that put lots of miles on his chopper, so he got in on the conversation. Since I applied what they suggested I have not had any issues with that aspect.
Here is the Issue and it may not be your issue, but it covers lots of BIGDOGS owned by Big Ridders. Take the seat off and look at the back side of the seat and see how thin that felt cover is. Under that felt cover sits a metal pan which forms the seat. The seat felt cover is glued to the underside of the seat pan with 3 M spray glue and that shit is so thin that it gets cut by the screws holding the battery cable on to the battery and could be shorting out your battery. When you go out and hit a bump and the bump kills the bike you blame it on the bump on the road.
I went to the auto supply store as suggested by my friend (May he rest in Peace) Mr. Ray Atwood told me and others to buy the rubber drawer inserts, or liners that are used in toolboxes. Just buy one and a can of spray 3-M Glue, (1) peel the felt cover off the area where the post may come in contact with the battery post screws and cut two squares about 2 inches and pile them on, they are self-adhesive and stick well to the seat pan which is all metal. (2) after you have done that to both sides of the seat felt cover spray 3-m Glue on the back side and glue it back on.
If that doesn't work for some of you, check your rear fender wire harness and make sure. there are not exposed wires rubbing against the inside of the fender or connector.
Good Luck
