When you start the troubleshooting process, disconnect one battery cable and put the heaviest 12V lamp you can come up with IN SERIES with the cable. That way, if you come across the short, all that happens is that the lamp lights, instead of blowing the fuse link or melting the harness
An old headlight, or stop / tail lamp socket, you can even twist both wires together and use both lamp filaments. Easy way to hook to the socket if you cannot solder, is just clamp a length of wire to the metal socket shell with a worm drive hose clamp
First thing I'd check is to see if the alternator developed a short.
So................
Hook up your lamp
Use a test lamp and probe around, you probablly blew the fuse link. For now, you can just wire around it temporarily
With the fuse link hooked up, the lamp should light if the short is present.
Unhook the alternator output wire and see if the short goes away. If not, pull fuses one by one. Pull the headlight switch connector off.
Look around for burned harness areas, in the engine bay, and up under the dash
AND if that does not show things, you are probably headed for dropping the column, pulling the cluster, and untaping some harness(es)
