I think it was 88, where they drastically changed the windows and locks. Got rid of the troublesome lock solenoid, and relay, and went to actual switches for the locks, instead of using the lock button movement.
The separate harness runs against the firewall, behind the defroster duct, and goes from door to door, and connects to the main harness behind the heater control. I know it definitely changed for the 88 year, but think it also changed several times with the changes in wiring harness connectors.
If the parts truck is the older style, I would not bother, too troublesome, and you cannot get the lock switch & solenoid if they break down, which they do. I would be surprised if they work in the parts truck.