Most I know do what Cab says and run the alt output wire to the battery side of the cutout switch. Another option is like I did years ago on my bracket car and that was I put a toggle switch on one of the field wires and ran it inside the car so I could kill the charging system when I made a pass and you can also just kill the charging circuit when going thru tech with that toggle switch in the car so it dies when the kill (cutout) switch is turned off. It is alot less wire to run if you just tap into a field wire and run it in the car within the drivers reach on a toggle switch. I burned out a rotor on my bracket cars alt so thats one reason I would kill the charging system when making a pass. Ron