Yeah, I screwed up. I put the battery in backwards. I my defense, it was dark. And thank you Ford for making both battery cables black and long enough to be swapped. Initially there were lots of sparks and smoke. The battery light is on in the dash. I'm sure I will have to check the alternator. What I am trying to pinpoint is what burned up under the hood that made all the sparks/smoke. I can't find any burned wires. The sparks came from the area of the negative block (where all the grounds connect at one point along the passenger fender). Which wires would have a fusible link around there?

P.S. The truck fired right up when I put the battery in correctly.

 

If you can't find any visibly burnt wires, then the next step is to start checking them w/ a meter or test light. Meter would work better for the simple fact that you can get ohm readings vs. just a light. I'd be looking for the wire(s) that have a lower resistance in comparison to other wires of the same gauge.

Others may have an idea of what to look for, but that's a method to help you find it.