With my old motor i had the voltage regulator isolated from the ground and had one of them hood alarm buttons set up on the throttle. at full throttle ground losted, no alt charge. I killed a tenth of a second. but i also removed factory fan and installed electric water pump at the same time. The reason i didn't us the alt kill on my new motor was because the fans pull on the battery enough that i had to bring a generator and a battery charger to keep the battery charged enough to start the car, if i went several rounds.(I have a better battery now as well)