The RED GREEN night lights.
You know the 3 foot long tube you insert into the slot at the
rear of the boat.....and front.
Are those female connections supposed to be hot all the
time or just when you turn the ignition key to on?
I agree with makomark, lights, radio, bilge pump should all be powered with a switch that way you can sit in the middle of a lake at night with your at anchor lights on and the engine off. You mentioned old wiring, that also might also be part of your problem. Your problem may be corrosion, poor ground, faulty switch. Are you getting 12volts to the fuse panel? Are you getting 12volts to the switch? Any connections in the circuit? If so pull them apart and check for corrosion. Any crusty brittle wires or sections or sections of wiring that are brittle? Any inline fuses? Pull them apart and check for corrosion. Battery posts nice and shiny? I hate checking for electrical gremlins, you need to be a contortionist. Take your time and approach the job in a methodical way.
Yea good grief what a mess. I think this boat was left out in
the open even though the interior is in good shape but there
is corrosion and I have been repairing wires.
I have all the bilge fish tank pumps working and I'm working my
way forward. Nav lights are next.
I hate trying to figure out other peoples wiring strategies.
Yea I do use good crimps and heat shrink. Problem is what the
previous owner(s) did, which is what I'm taking my time to
figure out. These people should leave it alone if they can't
even wire a one button on off nav light.
I will fix it but it will take time which I have.
I had the same problem and traced it back to the rear of the boat. Turned out to be corroded wire, which I replaced with marine wire and rubber wire shrink wrap. Also cleaned up the ground and have not had a problem sense. Hope that helps.