Taurus Transmission Issues

Hello everyone! I have a 95 Taurus GL, I’ve had to replace the transmission once before, it originally had an AX4N, but I replaced it with an AX4S along with the PCM. Even though it was a scrapyard find, it had very clean fluid and shifted flawlessly (I assume it had been rebuilt)

Anyway, the problem started after about a thousand miles or so, when you’d first start it and put it into gear, it wouldn’t move!! It took several seconds (sometimes 30+) to finally engage and when it did, it did fairly hard. Then one day the car just wouldn’t engage at all! So I left it parked thinking it was the pump shaft and didn’t mess with it for weeks.

Recently I decided to mess with it again. I was fully prepared to pull the transmission to see if I could find the problem, but decided to try and unplug the harness going to the valve body since I read somewhere that puts it into failsafe mode? Anyway, to my surprise it moved! I was completely confused until I started inspecting the wire harness and noticed it was against the exhaust! A few wires were burned, but not too badly. I pulled the entire harness out, inspected it, and fixed those burned wires. After putting it back in, it still has the same issue. (I also used a multi-meter to check continuity) I also tried replacing the PCM to no avail.

I was thinking maybe it killed something like the shift solenoids or maybe the EPC? But from what I can find online I’m not sure that would cause this specific issue.