Hot ammeter

That's where we differ. I've seen original last better than copies, and I've seen original worse than some hacks. Engine compartment takes a lot of abuse. Interior can be fine, or not. Leaks behind the instrument panel can cause problems - might be what we see there. Hacks, replacement headlights, poorly done stereos all can cause one or more problem spots.

What we see in the photo is rusty stud and damaged and overheated wires. The question is why? I've listed the typical causes for that type of damage. Find the cause.