Can anyone confirm what years and models have compatible wiring harnesses? (I've seen older threads that I don't have permission to update, or aren't relevant to my question)

Here's my issue...
I have a 95 Eclipse GST and the owner before me re-wired alot of the interior wires behind the steering column and under it. There are a lot of wires that got melted together and it's a complete disaster. I don't know what caused this guy to go through and screw everything up, but I'm having issues with the CD player turning on with no key in the ignition, when I turn headlights on, brights come on too, but half-way, and drain power. There's no in between. My whole gauge cluster is dim. I'm not sure if a chassis wire harness would rectify this issue entirely, but I don't think it would hurt.

Please advise, thanks.

Edit: I've purchased a repair guide for the wiring diagrams, and etc. I'm planning on taking the dash out and seeing the total effect of damage sometime soon, as I'm just now selling my daily.