I'm considering installing an auxiliary battery in my
'88 camper.  I've looked through the list archives, and
I think I know basically what to do.  However, I still
have a couple of questions:

(1) By what route have people run the wire from the starting
battery to the auxiliary battery?  Under the carpet?  Under
the floor?  Do I drill a new hole in the starting battery
compartment?

(2) How much amperage will flow across that wire?  I need the
amperage to figure out what size wire, relay, and fuse to use.
If I have a 90 amp alternator, do I need to be prepared for 90
amps on that wire?  If I want to be able to jump start my
(dead) starting battery from my auxiliary battery across that
same wire (I could put in a by-pass switch across the relay to do
this), then how many amps are there during a jump?

I should mention that I'm currently leaning toward putting in
a new relay, rather than using the fridge relay.  But:

(3) If I were to use the fridge relay, is the existing "+" wire
from the starting battery to that relay really heavy enough to
handle the current between the starting battery and the
auxiliary battery?  I realize many people have used it, but
it looks kind of thin to me.  If I use it, should I add a fuse
to it?  Similarly, is the relay itself really heavy enough?

Thanks for the help.

                                           -Steven Sittser