My cutoff solution
Salvation came when I was scrolling through the wiring diagrams and noticed a relay called "Ignition". It turns out this relay powers up 6 or 8 fuses in junction block 2, among them Inj 1 and Inj 2 which power left and right bank coils and injectors.
To make a long story short, I found on my car, a 2000 SS, that the ground for the Ignition relay, G105, were the ones bolted to the radiator support. I simply tied them together, then ran a wire from that junction back to one side of the cutoff switch, then ran a short wire from the other side of the switch to the bolts holding on my switch thus completing the ground circuit. When the switch is shut off the relay opens and the car shuts off, nice.
I'm not sure if all years are wired in the exact same manner, but if you undo the bolts on both grounds on the radiator support and get a "crank-no start" you can use the same system I did. I hope this helps make someone elses life easier.
Probably better to kill the switched 12v feed to the relay instead of killing the ground.
www.madelectrical.com. LOTS of good info on that site, concerning this topic.
killing the injector relay will shut off the engine, but it wont stop the fuel pump, in the event that you flip the car, and God forbid, the fuel lines are cut, continuing to spray fuel all over the place while the car and you burn to a crispy man-mc-nuggett.
it's a good thought, but be to safe about it, look at ALL the angles.


