and yes, like you said something was drawing some amps for sure. My guess is that like most everything else on the boat, the PO did little PM on this system. Could have been some internal corrosion because the plug is located in the same compartment where the fresh water system was spraying water because the factory did not install the C-clips to hold the PEX fittings in place. So no, I don't think it was melted from the factory, but yes, a melted hole is very suspicious.