[truckster]

My brand-new L31 Vortec cranked over once and then wouldn't start. I had rewired everything and put in a new battery and new starter. It was driving me crazy for a couple of days, until I remembered that I had painted clear satin ceramic on the aluminum brackets to keep them looking good. I removed the cable from the bracket, sanded off the paint, and it started right up.

The moral of the story is that sometimes it's something really simple, so as the others have said, start with the cables and work from there. A remote starter switch is also a good idea. You might want to pull the starter and test it with jumper cables, too.