1993 Suburban. Drove fine to work. when I went to leave there was an electrical short from the starter to the exhaust(Rubber cover must of melted) I got under it and got them separated. Now, nothing after the ignition works(stereo, heat/fan, clock, starter, etc.) Battery tested fine. Fuses appear to be fine. no loose connections around the fuse box.... Oh yeah! And the moment I turn the key to on position, the horn starts going constant with no pauses. Car has no alarm on it! I do not know where the relays all are or which ones are what to change them either

 

double check those fuses and check the mega fuse on the firewall from the battery....
check the cables to make sure they did not melt and are not conducting enough current to the rest of the systems...