so hero what you are saying is have a configuration that will enable me to ensure that the nuetral part of the circuit is at earth potential at all times by connecting it to a pipe, stake in the ground or chassis like Bill suggests as well as the nuetral of the battery. It sounds like the sensible mans choice to me.
I figure this is best done by wiring all the nuetral wires to the same bit of track where I can have a single wire which will connect to the negative terminal of the battery and also have another wire which will connect to ground, how does that sound? i.e. have all the blue lines in erics diagram connected to a single track where I can have two wires leaving it, one to earth and one to the negative terminal. by the way eric thanks for that diagram it is well appreciated and so has all your other help been.
My only doubt about this idea of mine is will the track I'm talking about connecting all the nuetral wires to be able to withstand the current I'm assuming will flow in it, or is it not worth worrying about?