Thanks Klaus. I got the problem solving sheet. Since replacing most of the locks the central locking works intermittently but most of the time doesn't work but at least the rear doors aren't remaining locked. I replaced the drivers door lock and the wiring loom in that door but still no joy. The problem solving sheet makes reference to central locking relays but I can't find these on the car. They are certainly not in either of the fuse boxes. I have a feeling the problem is in the whole central locking/alarm module which is just not providing enough power to the door lock motors to make them unlock, they click and make noises but won't actually unlock. I'll keep you posted. - Gus