Heres some notes I wrote down from putting an early style m5r2 with the 89-93 wiring harness into my 1994 SC - I used a spare 94 transmission wiring harness connector and spliced them together. I dont feel like going through it all and sorting it out right now, so heres just what I have written down ..
Re-Wiring the 89-93 Manual Transmission Wiring Harness with 94/95 Connector
Backup Lamp Switch - [93-1]
C210 - PG [150-2] 1994 EVTM
C291
P/O Wire - Hot in Run, C291
Bk/Pk C210, no 3
Starting System - From (CPP- Clutch Pedal Position sensor ) - [20-1, 20-2 ]
C210, no 1 R/Lb from CPP
C210, no 6 W/Pk to Starter Interrupt Relay
( Both W/Pk on manual Transmission - With a Jumper )
Wires had different end connectors so could not be re-pinned into the other harness, cut and soldered
Park / Neutral Position Input - [ 23-8 ] EEC 3.8 SC
C210, no 12 - GY/Y = GY/R - Return Signal EEC Pin 46 - Spliced to CPP signal on C291
C210, no 11 - LB/Y = P/Y - EEC Pin 30, Park Neutral Position Input
Manual Side = Harness Side
Speedometer Gear - [ 64-1 ]
VSS = OSS
Manual = Auto
PK/O = DG/Wt
GY/R = GY/Bk ( Ground )
Black / White = Ground on 89-93 Manual Harness )
PNP + CPP
C210 P/Y and GY/Y are Spliced to C291 which goes to the CPP
- Dan