Stewart, what if you are knocked out? The switch must accessable from the back of the car so track personnel can cut power.

The switch must be on the positive side because if it is on the negative side and in a crash the neg. cable is cut or chafed it will provide a ground making the switch useless.

Call Mark at Mad electrical 559-539-7128 he will sell you all you need to do it right. Website is www.madelectrical.com

I followed his instructions and have had no problems at all.

The switch can be on the main positive cable but I had a hot start problem with mine wired that way. Mark's way of wiring it solved all that and is NHRA legal too.