Right lads, since im going to be making a SSM1 (<1997 DIAG)cable, i want to document and record everything here and hopefully it will help us out as a community. 

ill be following these instructions.

Shopping list:

1) Audio harness adapter for Legacy 84-97 (Autoleads: PC2-29-4)

2) FTDI TTL-232R USB to 5v TTL cable

3) 2.54mm 0.1” Pin Strip (Maplin JW59P)

4) plain matrix board with 1mm holes on a 2.5mm matrix (Maplin: JP54)

5)  LM358N Op Amp

6) 10k Ohm minature potentiometer

7)  4.7k Ohm resistor

8) 0.1uF Capacitor 35V

9) BL17 8-way DIL socket

10)copper wire 0.53mm

ill continue when i manage to order all the stuff

 

Excellent stuff