Toasted wiring harness

[ujsf01]

I would surmise now knowing the temp gauge failed, that at some point, that printed circuit overheated, melted the plastic away from the metallic leads inside, and resulted in a big time short. Almost be willing to bet the green wire to the temp sender has a short to ground somewhere as well. You'll be light years ahead with the new harness. AA has a loaner program for the correct crimpers you will need if you don't own them. There are two different crimp tools you'll want to have to do the job right!