Yeah something melted and arc welded itself to ground. Could be inside the fuse box or somewhere inside the harness itself. Potentially even inside the alternator. Could even be as simple as inside of a relay. I would start with the relays as mentioned earlier. Just replace them. With the extent of the electronics in today's vehicles, might chasing several components that are damaged..... And shortened the life of others. After addressing the weak links.... all relays and fuses..... I would backtrack from that starter cable that got shorted. Assuming you disconnected the cable to the starter and shortered it the block or to a ground, first stop is probably the alternator. From there the short could be fed into the harness.... And I'm not sure a schematic is going to be much help. Because you will need to unwrap the harness and inspect the actual wires along the path of the short. What you're hoping to find something that broke the connection to everything else upstream..... In effect, acting like a fuse.
You may want to get someone who's an automotive electrician by trade involved. This could get quite complicated. Don't forget, you not only grounded out the positive side of things, you sent current backwards up through the ground connections of various modules and components. Which I'm guessing may actually be where the problem is. Remember, there's no fuses on the ground side of things to protect the components.
