Quote Originally Posted by Matt93SE View Post
since the field coils on the alternator are cut, it effectively cuts "all circuits". All sources of power are on one side of the switch, all users of power are on the other. You flip the switch and the car stops. right now. What else do you want?
Maybe that's good enough, and as I think about it, maybe I'm colored by the fact that my car has its battery in the back. I was trying to avoid having any electricity in the engine compartment. But I suppose if the battery is in the engine compartment, that's not a realistic goal.

But it says "all circuits" and as long as there's a circuit from the battery to the alternator, to the engine ground, back to the battery, it's hard to argue that it meets the letter of the rule.