Factory ammeter

I chocked it up to old bad wires. From what I could tell, and I'm no expert, but it looked like the source of the issue started with the wire overheating and melting the plastic around it in one spot then just spread into the cluster of wires it was tied up with.

Yeah, that "welded splice" deal behind the cluster wasn't the "best" idea in the world.......although honestly, I've seen very few failures of them. Mostly melted bulkhead connectors. Although mine has zero signs of even getting hot, that's one mod I might do. Separating those connectors and bringing them through in their own dedicated grommet through the firewall. Maybe. lol