The original wiring on our '81 CHB 34 is wonderful but previous owners have
not added things neatly such that I really must re-wire all the overhead
electronics.  (None of my gauges work correctly!)

I am not very good with electricity but it looks like all the wiring is done
with positive 12V DC only. That is, I can find +12 everywhere but can't find
-12.

Is it possible that there is a "master" ground where everything is routed?

<<it looks like all the wiring is done
with positive 12V DC only. That is, I can find +12
everywhere but can't find -12.

Is it possible that there is a "master" ground where
everything is routed?>>

Ed,
Yes it is very likely that there is a ground buss bar
somewhere near your electronics.  Look for a copper or
brass flat bar with multiple brass screws, terminating
a number of wires, most of which should be black.  You
won't find -12 volts there, but very nearly zero
volts, which is the definition of a ground.

=====
Mark Richter, M.E., aboard M/V Winnie the Pooh,
custom Morgan 46 Pilothouse Efficiency Trawler.
"Mark's Mobile Marine" electrical systems repair & consulting.  Homeport Stuart, FL

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