Edited: another fuel/temp gauge thread, but turns out the harness is melted together

I started unwrapping my under dash harness from the bulkhead connector and I found another section of melted wires starting a few inches back. Looks like the charging circuit got hot and melted some surrounding wires. The red wire is bare with plastic melted. This probably happened years ago.

I guess the bright side is my car didn’t burn to the ground.

I think it’s time to remove the under dash harness and investigate and make repairs.

I wonder, at what point should I just buy a new harness?

Thanks everybody.