The newest fox is 20 years old, even a non-hacked harness is going to almost always have issues. I'm not sure if anyone is making replacement harnesses these days but it might be worthwhile for someone to start.
2000 Mustang GT Steeda #0048 34k miles. 99 Cobra 4V swapped, FTBR IRS swapped, exhaust, tuned by James Gordon.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.