I'm assuming amps.
So I took the center section of the bulkhead apart first and found this black wire was fried and separated. I'm again assuming, this is a ground since it's a larger gauge black wire.
What do you mean "assuming amps?" To read amps you need either a DC clamp for your meter or read the circuit in series. The only grounds in the engine bay are small gauge for lights, and straps for the negative cable. Color does not indicate use always, there's main alternator wires that are med gauge - #14 to #10 that are main current carriers.
Replace that entire mess, the copper will oxidize black at those crimp splices.