I've still been trying to troubleshoot this every evening after work. One thing I tried this morning was I went ahead and cut the yellow/black wire that goes towards the rear of the vehicle about 2 inches from the brake switch connector. The fuse still shorts as soon as I try to insert it. Pretty sure that tells me that the short must be in between the fuse box and the brake switch connector. I wonder if there's a relay in between those two points though? There's several relays right next to the fuses under the dash, but they're not labled anywhere, so I don't know what they're all for. I'm guessing the problem can't be in between the fuse box and the battery, else the short would simply burn the wire in two, right? This is being a real pain to figure out!