Could the ammeter be had causing this? If so, how do I test it before I put it all back together?
That appears to be a factory junction, probably the main junction.
Start by looking at the
diagrams showing how the power flows .
Then look at the damaged wires and see what they connect to.
The fuseable link at the starter relay was still intact but the wire was melted. Bizarre
.
Take a picture there as well.
Not neccessarily strange at all. It depends on where the short was, where the power came from (was the engine running?) and where the highest resistance was in the path back to ground. We know there was enough heat at bulkhead to break at least one connection.
It is important to get the electrical diagram for your vehicle. If you don't want to buy, take a look around the web, people have posted portions electrical diagrams here as pictures and there's even some pdf floating around out there. I know that 'cause I was looking at an early 70s Dodge diagram within the past month or so.
The diagram will show the wire gage. It will show the insulation colors. It will show where the wires are supposed to connect. It will show the fusible link or links and there locations.
Again you can use my simplified factory diagram as a starting point. Much of it will be the same or similar. (Differences will be the bulkhead numbers, link location, and of course the alternator will have a ground wire to the regulator.) Another difference may be the wire sizes and some of the colors.
