The Vehicle: 97 Cherokee (2WD originally) with a 96 AW4 for 4WD.
Problem: P0700, P0705, no overdrive. Third gear is fine around 40mph, but I never get OD later; likely cause by the TCU not receiving the OD signal (see additional info)
Additional Info: The 97 wiring harness was modified to accept a 96 style NSS... Not my doing.
Problems eliminated: Originally thought the NSS was bad - Multiple NSS's swapped, cleaned, etc... Some older NSS's which were actually broken gave different CELs. I've landed on about 3-4 spares that work fine. Then realized that the TCU is likely not getting the OD signal based on the 96 input. No missing or problem fuses.
Research: I've looked a lot of places and waited a while posting because I thought I could figure it out without replacing the wiring harness.
My primary reference point was this (had plenty of secondary references): https://www.naxja.org/forum/showthread.php?t=1053970

Question: Is it possible to get the OD signal to my current harness by splicing another wire, or should I just get a new wiring harness and try to figure this splice job on the other side.

 

*Bump*