I caught it just in time by accident. Decided on the spur of the moment to go for a short run on the IC. When I grabbed the plug it was hot. See the photo of the wires from the backside of the socket. They are melted together. When you put a VOM across them there is no longer infinite resistance. They charred at the melted point and were passing current with no load from the boat. I suspect the fire was just a matter of hours more if I had not decided to go out that morning.
