Electrical problem

Hello, List. I need some electrical guidance. I'm keeping my boat at a friend's personal dock. The dock is wired for electricity. All power to the dock goes through a single GFI breaker. I have made a shore power cord for my boat that plugs into an outlet on the dock. There are also a series of lights on the dock that plug into the other receptacle in the same outlet. If my boat is connected to shore power and the other dock lights are then plugged in the GFI trips. If my boat is /not/ plugged into shore power and the other lights are plugged in they work fine. Also, if some other device is plugged into the outlet instead of my boat, then the lights are plugged in everything remains fine. This happens even when the master AC breaker on my boat is off. The polarity is correct on the shore power cord. Any ideas? Thanks, Matt Cal 27 Mark III

Well, thanks all, for the help. I've found my electrical problem but I still don't know what it is. It's this thing: http://mwrohde.googlepages.com/Thing.jpg With this hooked up I had continuity between my neutral and ground, with it out I don't. The white wire of this doodad was hooked to the main breaker where the white from the shore power hooked. The green was attached to the ground bar. What the heck is it, do I need it, and if so where do I get another one? Thanks, Matt Cal 3-27 --- In Ca… [at] yahoogroups.com, "mwrohde" <yahoo@...> wrote: > > Hello, List. I need some electrical guidance. > > I'm keeping my boat at a friend's personal dock. The dock is wired > for electricity. All power to the dock goes through a single GFI > breaker. I have made a shore power cord for my boat that plugs into > an outlet on the dock. There are also a series of lights on the dock > that plug into the other receptacle in the same outlet. > > If my boat is connected to shore power and the other dock lights are > then plugged in the GFI trips. If my boat is /not/ plugged into shore > power and the other lights are plugged in they work fine. Also, if > some other device is plugged into the outlet instead of my boat, then > the lights are plugged in everything remains fine. > > This happens even when the master AC breaker on my boat is off. The > polarity is correct on the shore power cord. > > Any ideas? > > Thanks, > > Matt > Cal 27 Mark III >