New Subject line
Another aspect of using the Surepower 1315 instead of the stock relay has to
do with moving the internal accessory wiring over to the aux battery.  The
normal usual way to move the accessories over is to run an extra wire from
the aux battery to the accessory fuse at the fuse block under the dash, pull
the fuse (fuses depending on year) and provide the 12v to the non-hot end of
the fuse holder.  But when you install the 1315 there is a wire from the
fuse block that WAS running 12v BACK to the aux battery relay.  This can now
be used to run 12v FROM the aux battery to the fuse block and avoid having
to run another wire forward.
BUT, at least in my case, this only worked after some other surgery on
wiring at the fuse block, it was NOT straight forward.  I'd still be trying
to figure it out.  But Paul Druzyk from BC was helping me and he knew what
he was doing.
So don't ask me for the details on this wiring change because I can't tell
you exactly what was done.  Paul labeled all the wires he changed and I'll
be able follow it if I need to in the future but I didn't make detailed
notes or diagrams at the time.
Just pointing out that in the case of the Surepower 1315 the Elegance of
Simplicity triumphs.