Tail Light Ghost

[Marine-58]

Could use some advice.... Every few weeks my rear tail lights and turn signals stop working due to a blown fuse. Thought that I had found it with a + wire that rubbed through to the frame. Taped it up and was good for a few more weeks. Then the fuse blew again. I have run the wires all the way from the front to each tail light and cannot find any issues.

Hopefully someone has an idea. The only thing I can think of is maybe the fuse block could have an internal intermittent short that only affects this one circuit? Maybe this weekend, re-run all electrical to the rear?

I'm an old fat guy and getting under a vehicle or dash is not as easy as it once was...