Join Date: Apr 2007
Location: St Thomas USVI
Thanked 35 Times in 33 Posts
Rep Power: 10
Is it safe to assume that you are in the US and have a single 30 amp shore power cord?
My suggestion would be to start at the A/C panel with a A/C tester. Ideally you will have a three wire cable (white, black and green) coming from your boat receptacle to the panel. If you can locate the cable attachment point at the panel you then need to put your tester probes between the black and green (hot and ground). If you see nothing then you need to go back to the actual shorepower receptacle on your boat and do the same thing. If you are confident your shorepower cord is correct then it must be the actual receptacle, or the wiring connection to it that your cord is connected to.
If you see 120 volts then there is a problem between the panel and the receptacles. Follow the wiring from the panel to the first receptacle. Remove the receptacle so that you can access the wiring on it. Using your tester place one probe on the ground wire (green or bare) and one on the black. If you see voltage then follow the wiring downstream to the next one. If you find a group of wires and a wirenut or a crimped connection, wiggle it around and see if that is where you are having connection problems. If that is the problem, make a better connection.
There are so many variables that could be causing this that I could type pages of things for you to try. I suggested what I think is the most likely. There is always a chance the outlets where wired with a two wire cable instead of three. I have seen people not bother to hook up ground wires before. I have seen rodents chew thru wiring too. Have you looked at the physical condition of the wiring from the boat recptacle to the A/C panel?
What kind of boat is it? How long have you owned it? What prompted you to test it for proper wiring, were you having some sort of problem?
I hope you figure out the problem and fix it properly. The ground system is sort of the "liferaft" of wiring. If all else fails it is there to save you and trip a breaker.
Last edited by FarCry; 10-30-2008 at 10:16 PM.