Was set to fish a 2 day championship tourney this past weekend, fished Saturday and after fishing most of day, Starting Battery was weak and would not crank the big motor. Took trolling battery and put it in place of starting battery to get back across the lake, when hooking up battery caused a spark. Once all was tight, no power at all. Took Cowling off and 100 Amp Main Fuse was blown. Put spare in place and boat ran fine for the next hour or so, while I was letting wind be my trolling motor. Bought new battery and installed to be ready for 2nd day of tourney this morning. Put motor on totor and headed to lake, when got there, no power again, except this time a horrible burning smell from under the cowling. Removed cowling and under fuse panel, plastic cover with 4 screws was very warm to the touch. After removing screws it appears something that looks like a relay was hot to the touch and plastic covers over cable ends were burned.
Any ideas on what could have happend ?