I had a similar problem on my mums focus. Turn out to be the rear drivers door lock/solenoid. Couldn't say which one it was as I iust replaced both from a scrappy. Sounds like you might have a problem with the solenoid if it's not moving the lock enough. First I would try greasing the lock (easiest thing) then disconnect the lock solenoid connection multimeter on the solenoid connector lock/unlock and see if everything is getting a good feed. Sounds like it might be an earth problem, so check the earths.. Only things I could think of really. Sounds really daft but check the window hasn't caught the door loom. I had a problem with my speakers where te window had caught the door loom and damaged it

Hi I've got a 1.4 corsa sxi petrol car. I'm having problems with the central locking when I'm using the key fob. The central locking will sometimes activate when I'm going along. When I pull up and take the key out of the ignition the doors again lock. The fob works to lock the car but rarely works to open it, it's as if the handle us broke. When I try and open it with the key fob the plastic bits that go up don't go up enough and then lick. Has anyone got any ideas?