Yikes ... you really are continuing this !! (I missed until now that I
had to advance the thread to the next page)

You bought another tool ? A tool that only works with live power
flowing ?

Hey man, I am going to underline spit on your grave underline if
you kill yourself or someone else, after all these warnings.

Knowing now you have a 50' with a generator and two shore power
cables, my previous estimates of cost to have someone check this out
when your done is admittedly going to be low, my estimate of how badly
you need help has increased 2 fold, and my belief you can control your
total costs of the project by doing some of the work yourself is
quickly diminishing. (you mentioned the wires, even though all red,
are already marked; using an ammeter creates opportunity to cause new
problems and costs)

In answer to your questions:
- Using an ammeter the way you describe is going to fustrate you, not
really help, and is dangerous despite the appearance of the insulated
grips and probe.

DANGEROUS: This tool only works while the power is flowing, and
requires you to get at one lead at at time. Unavoidably your going to
start opening up panels, twisting individual wires out of the way to
get the probe around the other, etc. This will stress physical
connections to get at those leads creating opportunities to cause new
problems, and expose yourself to electricity, burns, or fire.

FUSTRATE: Ammeters don't find problems, so much as they identify
symptoms of a problem, often very far from the source. Short
instruction manual, appears easy to use, but this tool will send you
in circles. Next you will be disconnecting wires to simplify the
circuits your looking at ... you know what I mean, you probably have
done so already. Changing wiring can also appear to have fixed the
problem, but all you have done is prevent the ammeter from seeing the
symptom of a problem elsewhere on the boat. Ammeters read magnetic
fields. A little like ghost hunting, although based on real science,
can be equally as unrewarding as ghost hunting. Wouldn't your rather
be boating ??

NOT REALLY HELPFUL BY ITSELF: Once you get things in balance, it won't
prove anything either. It's a one way street. Being out of balance
indicates a problem, but being in balance dosn't get you in the clear,
you easily can still be lacking ground protection in a specific
circuit that could kill someone.

Also ... how about the math. A 50 foot boat has got to cost you,
including depreciation, insurance, yard services, wear and tear
(corrosion) of boat and electronics even when not moving, of upward of
$50,000 a year. If you have 20 opportunities to go boating each year
(due to weather, hurricane season, wife needs you to do work around
the house, kids have soccer, etc.), each weekend you loose is worth
$2,500. Why not cut your losses and get it taken care of by a pro?

What marina are you at / slip / name of your boat ?