The fto is haunted with problems with one or both of the central locking motors not working. I have repaired several and have taken pic of the offending item below.
The brushes in the motor wear. The green disk is a thermistor to protect the motor from overload. If you take out hte motor I am pretty sure malpins or radionics would have a replacement. The brass gear on the end of the shaft will come off pretty easy.