The various drag racing sanctioning bodies require a battery disconnect if the battery is mounted in the trunk. What is this supposed to do? I currently have a switch in the negative cable. The positive cable goes to the starter solenoid on the starter. To that same post (on the starter) I have connected the single wire alternator wire and a wire leading to the fuse panel, etc.

If I flip the battery switch, the battery will indeed be taken out of the loop, but the engine would probably not shut down. I don't know if this is the intent and hence my original question: what is the shut off switch supposed to do?

Ed

yes the engine is suppose to shut off on your disconnect switch in the back of the car that you installed run the + lead from battery to one side then up to the starter on other side this will take the battery out of line BUT NOT THE ALTERNATOR for that you need to run the big read wire back to rear of car and through same switch to remove the alternator also think about it like this you can start the car and remove the battery and the car is still running right so now you need to remove the other 12vdc source from circuit which is the big red charging wire