Do yourself a favor and put a relay in that kills the alt wire from the battery to alt.

It's great to have a car with a cutoff switch that still burns to the ground because the alt wire is hot and the source of the fire. Flipping the switch to kill power does no good.

This is the way I do mine. Once you flip the switch, NOTHING is hot beyond the trunk.


Here are a few others:

This one is the same as the above except the extra relay for the alt wire.


Very basic, but, legal


Alt relay example