Fred T is right on target. Sounds like time for new wires, and not just the ones that burned off insulation.

Someplace in the primary positive circuit between the battery and the last place to burn you had a direct bare wire contact to ground. The battery pushed all the amps it could.

It would be a good idea to try to find where the bare contact occurred and trace back to the battery from that point. Things other than the amp gauge may have lost all their smoke or been damaged by the high amperage and be laying in wait to fail at a later time.

You are very lucky and I am glad you didn't have to write about the fire truck coming to visit.

Drivin' down a 2 lane country road in a stovebolt.....cowboy, it don't get no better than this!

1946 1-1/2 ton Chevy
"Ol Blue", or "THE BIG 'UN"