Here's the thing:
ANYTHING that bad is VERY likely to have melted other wires in the harness causing "interesting" shorts and cross connects
There is some stuff in Mopars that is NOT FUSED except for the fuse link, and the fuse Link CAN HAS AND WILL not always protect against what you see here. JUST ONE EXAMPLE is a shorted alternator.......which can/ has burned/ melted the engine bay harness from the alternator all the way to the firewall, up into the dash harness to the alternator, BACK through the firewall to the fuse link......and then blow the fuse link
I'd yank the engine bay harness out, "pin" it out on scrap wood, document it, unwrap it and examine / rebuild it, or find a replacement, either used or "repop." Try to "notice" what is melted worst to find what the cause is
THEN you might be pulling out the under dash harness as well
Some main things that ARE NOT FUSED (unless the wiring has been modified:
1: Alternator charge line, the big black going from alternator around the bay, through the firewall, to a splice in the panel harness, back out through the firewall (red) to the fuse link
The entire ammeter harness, and the ammeter can short
The hot buss supply line from the "welded splice" in the ammeter circuit TO the fuse panel
The main hot going to the ignition switch
The ACC buss going (switched) from ignition switch to the fuse panel
ALL the ignition "run" wiring out through the firewall, supplying ignition system, regulator, alternator field, and some smog doo--dads
Starter "start" yellow wire feeding the start relay
Coil bypass circuit, brown, "IGN2"