On Fri, 24 Apr 2009 13:21:06 -0700, "Calif Bill"
wrote:

Motor & power to console both showed 12 volt
when testing positive to aluminum.

Two problems. The battery Positive is connected to the hull.

He said the hull was neg. It showed 12v when connected to pos.


In any case the engine, driveshaft and/or sterndrive will make a good
connection from ground to the hull. None the less, I don't believe in
using the hull as an electrical conductor, except for the lightning
rod. To digress slightly, get some really big magnesium anodes if you
have a slip in a marina where they mosty have stray shorepower current
in the water.

definitely wrong. And you should not use the hull as the ground / negative
for the electronics. You can see extra corrosion because of that. Run a
separate ground and power line to each device. Run the power from a good
fuse panel or circuit breaker panel. My consol electronics all have in line
fuses and run off a connector panel under the dash.

Even my 1930's design biplane had a row of fuse holders, a dozen of
them, along the bottom of the dash. My 1975 volvo had the fuses just
forward of the driver door, and you could find a blown fuse by feel,
even while driving. Those Bosch fuses had the wire exposed on the
outside of a ceramic plug.

If the wiring has been ****ed with, go over it wire by wire, testing
and attaching labels as indicated.

Casady