Shorting across battery terminals makes a closed circuit for the battery and shorts it. There is no way fuses anywhere else can do anything. I think putting a disconnect in the ground is the wrong thing to do because
1. Defeated all fusing and switching in opposite polarity. In effect this is similar to cutting the neutral in house wiring - kind of poor comparison I know.
2. Easy to bypass and steal vehicle. If in the "hot" may be harder to bypass for theft.
Dan Bentler
