Last week I posted to a thread about electrical wiring and such in a
Vanagon.  I made a firm statement that "You always put the switch on
the ground side of the load" or words to that effect.
David Beierl politely suggested I might want to rethink that
statement, that there was really no basis for it. But I was sure that
somewhere I had learned that, that it was the right way to put a
switch in a DC circuit.  So I racked my brain to try to remember where
I had learned such.  And did some circuits in my head (Ohms Law in
mind), went to the old notebooks and references I had from the days I
was making my living chasing electrons and then started some online
research on the subject.
And I was wrong.  I can find no justification for my statement about
putting the switch on the ground side of the load.  There is no
special reason to do that that I can find.
In fact, as soon as I thought about it for a short time there is a
reason to do just the opposite, place the switch on the hot side.
That way you are a little safer if working on a circuit with the
switch off, no juice to short out.
And of course, when at all possible, place the fuse or breaker as
close to the hot side as you can to minimize using the rest of the
circuit as part of the fuse :)
So I apologize.  And thanks the David for the polite tweek on the subject.