Different years had different kinds of switches and relays. I am not very familiar with pre-1986, but those cars used a four wire switch and relay. I think the relay was in the door, but I am not certain. 1986 and 1987 model years use a switch on the rod running to the locking knob with a relay in the Central Electrical Unit. In 1988 the switch was changed to one that fit around the lock. 1986 and on model years use the same Central Locking Relay (yes, it was upgraded on the way, but they interchange). If I have time this week, I will send you a picture.