Blown Fuses

[Toadhunter]

A friend of mine recently borrowed my boat for a week. He said he had a issue with the light fuses. Switch up the bow light works fine, switch down both bow and stern lights work for a couple of seconds and then it blows the fuse. Any idears? All wiring looks great,connections clean, just wondering if its a power surge from my motor.

[fish_boy]

If the light works from one spot and not the other I'd suspect that there is a short somewhere. Is it possible to remove the lights from the boat or at least take out the bulbs? If so take one light or bulb out at a time and it will narrow it down to the bow or the stern light. Then at least you have a smaller area to look at.

What type of boat is it?

[billditrite]

sounds like you could have issues inside your switch? you say "switch up" and switch down" what positions are these on your switch...is on and off marked on it anywhere? are there more positions on the switch?