issues with car electrical system

Help..I'm not sure what's going on..first off I have a 95 chevy 2500..both the brake light n abs light was on when got it..I plugged in wire for trailor hitch n pressed brakes to check lights n popped fuse replaced #1 brake fuse but it kept popping..so I unplugged the trailer hitch wire for lights..replaced fuse again..it worked this time so I decide to take truck up the road I got about 2 blocks from my house n smoke started coming up around the steering wheel..smelled like wires melting..I haven't a clue..I just changed the fuse that's it..any ideas..