Ignition solenoid wires melted

GM is famous for using the larger "battery" terminal on the starter solenoid as a convenient tie point for the other circuits, so double-check that no wires got left off. Those will start out with short sections of fuse link wires. Those are a smaller diameter than the wires they protect, making them the weak link in the chain, and their insulation is designed to not melt or burn. They will be a dull color, usually gray, black, orange, or green. To check them, just tug lightly on them. If they act like a wire, they are okay. If they are burned open, they will act like a rubber band.

On newer vehicles you will find a smaller battery positive wire goes to the under-hood fuse box. Be sure that connection is clean and tight. While you are at it, follow the smaller negative battery wire to the body and be sure that is tight and not rusty.