overcharging the battery HELP

I unwound all of the wiring the previous owner ran. I found the problem(s). First was the new plug at the bulkhead was not getting a good connection and causing ignition problems as well. Also the new harness that was taped up had a really bad in-line connection and needed to be redone. It now starts right up and charges correctly. Fixing things done wrong is all I do I think. Pretty much the last 5 cars now have had dumb things done to them.