All my brake lights do not work

I saw a thread already about peoples brakes light not working. I have the truck listed above 2500 5.7 HEMI. All my brake lights do not work. The only fuse that was blown was for the center high mount brake light and i changed the brake switch and still does not work. I changed the fuse on the chmls and then changed the brake switch and now the fuse is blown again for the high mount. The 50amp fuse for the tail lights are still good. I'm guessing the high mount light has something to do with the brake lights not working. I have worked on cars my whole adult life but still not that great when it comes to the electrical to troubleshoot. I have tried to figure out which wire is for the brakes on the tail lights and when the brake is pressed i get .003 volts really small voltage. All the turn signals, running lights and flashers work. I am at a loss.