All,
Auxiliary Battery wiring:
It looks like the existing wiring from the starter battery to the auxiliary
battery is too small on existing 86+ Westys. It looks like it is advisable
to  pull a new #6 or #8 with inline fuse from one to the other as part of
adding the battery isolator kit.

Note on use: I am looking at adding a 30+ amp amplifier for a new stereo
that will likely drain the auxiliary battery and I concerned that when the
aux battery is charging, while driving, it will draw too high of an amperage
across the existing wiring to the starter battery.

What is the best way to run a new connector wire? Locate it under the car or
through the car under the carpet?

Thanks for your insight.

Kevin