Last weekend Mike and I were working on project 300 ('87 F-250) when we both got a scare. The dash had just been put back together and we were going to start the truck up and see how it shifts. I first hooked up the negative and then as I put the positive cable on the terminal I felt and heard a spark. Something was putting a load on the battery. As I wracked my brain trying to figure out what it was...a wire running from a small fuel pump to inside the cab was creating one heck of a short circuit. Instantly the plastic insulation running the entire length of the wire turned molten. I quickly disconnected the battery and fetched a fire extinguisher from inside the Jeep.
The lesson here is make sure to have a fire extinguisher handy when doing electrical work. On second thought keep one around at all times.