OK, I took the factory Lt Green/Black wire and the Purple/White wire that runs from the DRAC to the VSS on the tranny in stock configuration on the 94 truck and cut it in the engine compartment. These wires are a twisted pair enclosed in black insulation. Take the ends and run them to the new PCM and hook them to terminal 20 and 21, respectively. The wires are color coded at the PCM. Hook into them but leave them intact (just "skin back the insulation without cutting the wire) and twist and solder the wires from the DRAC and you are done!