Electricity is like water. Follow the flow. When water comes to a dam or barrier it will go over, under or around it but always find a way to flow. Same with electricity. It will look for the easiest path to get to where it wants to go. I would strip your bike down (tanks, fairing off etc) and methodically go over every connection and ground. Just takes time and patience. Crack a beer on a rainy day and have at it.