T&T: Grand Banks 49 AC Wiring Panel Question

[Wayne Beardsley]

We have a 1981 GB49 Classic and I have a question about the AC wiring.
 There is a panel behind glass doors on the starboard side of the
engine room that has all of the AC circuits individually broken out in
graphical fashion.  This is for the "hot" wire of each circuit, what
would be the black wire if normal US color conventions were followed.
Toward the aft end of this panel, right hand side as you are facing
it, are two bus bars with numerous connections going to them.  I
assume that one bus bar is for the neutral wire (normally white), and
the other for ground (normally the green wire).  We apparently have a
wiring fault somewhere because there is zero resistance between the
two bus bars, or perhaps my understanding of their intended function
is incorrect.

Does anyone on the list have knowlege of these bus bars and know which
is neutral vs ground, if that is indeed their intended purpose?

Any suggestions for finding out where neutral and ground are tied
together since that seems contrary to ABYC code?

Is there anyway to tell from the Grand Banks 3 digit circuit tags
which wire is hot, neutral and ground?

Thanks in advance,

Wayne Beardsley