I did a similar change today, I found the new bootlid off the facelift or 4x4 lock mech wouldnt work. I believe these cars had a release handle by the drivers seat.

So I ended up taking all the locks and wires out of my 1989 boot to move into the new one. I also had to mod the lock hole a bit as the earlier lock barrel is a different shape.

And as for which does what, If I recall the wires on the passenger side are for the central locking motor, should be three connectors/wires and the wires on the drivers side are for the boot light and computer display.

Dan