I thought it might have rubbed through the insulation and shorted but Patrickt may be correct on this. A couple years ago my orange wire became loose at the alternator terminal and the carnage looked almost like some one hit it with a welder. I think the boot got trapped under the wire terminal and then worked it's way out leaving the connection loose. Fried the orange wire and insulation for a couple of feet and I had to replace it all the way to the fuse box and re-wrap the harness. Ruined the altenator to as the terminal insulation was melted all the way through the case.
