Okay this is all i can think of..
And im not sure how it works so bare with me i have two theories for ya..
The central locking works using air. When you turn the key there is a switch which will fire up the pump to either suck the locks down or open them with air. It is a two pin conector inside the door behind the door card which connects to this. Now when i fitted my electric windows i noticed mine had actualy come unpluged, but... my central locking still worked on that door. But mabey i knocked it while changing the electric windows???
So my other theory is.. it works some other way and that two pin connector is to sence when the Automatic window closer thingy is being activated. But then that could feed off the pump so... Basicly your best getting the door card off and having a look. Check the wiring to the key barrel area and trace it back through the door where it conects to the chasis this is where it meets the Dash loom there is another set of plugs. Also check all of the piping, there is small green/yellow pipe that feeds the air to the locks.
Hope that helps.. if you can make sence of it
