Duster fusible link wiring problem

How can you know unless you test it?
It could have a short in the bulkhead connector, the column connector, the signal sw or the headlight sw, or the brake lights could be stuck on, or the dome light was on, or the ammeter shorted to the frame, or the alternator is shorted, or a million other things, none of which have anything to do with the underhood harness. And that's just the factory wiring.......