1994-95 used the same ECM and the wiring was very similar. But the 94 used the 1st gen round steering column while the 95-97 used the newer column making each of those years 1 year only electrically.
The 95 is OBD1 with the 64 pin computer inside the cab, behind the glove box. The 97 has the OBD2 160 pin computer on the inner fender. Which means among other differences the connectors going thru the firewall are very different. 96 was a one year only PCM and electrical. 97-98 used the same PCM, but the 98 electrical system was completely new. So for practical purposes 97 was also 1 year only wiring.
Or to put it more clearly 94-97 were different every year electrically. On all 2nd gen interior wiring it seems something changed every year. You need to be same year, engine, transmission, body style, and similarly equipped accessory wise to swap harnesses.