Experienced similar problems on my 1980 boat #201. In 1998 I replaced and rerouted just about all of the wiring in the boat because I was going cruising in Mexico and didn't want any problems in the middle of nowhere. A lot of the wiring I pulled out was in bad shape. The rewiring was not difficult but quite tedious and time consuming because some disassembly of the boat was required for access. If you decide to rewire any part of your boat, I can probably tell you what worked for me, wire gage, routing, etc.
