About my headlight wireing

Where do the wires run for brake lights? I installed a ladder rack on top of the
van, and installed a shelfing unit on the floor in the van, running
along the left side of the van. After installing these two items
successfully, I jumped in the van, put my foot on the brake, and the
fuse blew, as well as several others. My question is, where does the
wiring in this van run? http://usautolighting.com