My kids like to play in my '46 1/2 ton.. The way it is wired now though the starter is hot all the time. if you step on the starter it turns over, even with no key.. I found a 200A relay at:
http://www.wiringproducts.com/index1.html
I'm thinking I'll fuse a wire to the ignition and let the ignition connect the battery.
Anybody ever actually done this?

Experience is the ability to recognize a mistake when you make it again....