On my disco II when I use the remote key our the lock/unlock button in the Disco the passenger lock moves a little but doesn't fully go up are down to lock our unlock. Right before this happened I disconnected the battery to take off and clean out the EGR valve so i don't know if it has something to do with disconnecting the battery our not. all the other locks work. Any idea's on what might be the problem? I was thinking if it was the door lock actuator the lock wouldn't move at all but not sure.

 

I took the door panel of and found a metal thing... that has 3 screws in it to secure the rod to the door lock had come off. One thing I would advise is not to remove the rubber window seal from the door panel first as advised in a Atlantic British video. I did this carefully with a tool similar to a paint scraper to gently pry of the clips. Will when I was popping of the clips under the rubber seal I bent the rubber seal and its almost impossible to make it look like new again since it has metal in it and also the metal came through the rubber a little leaving a small hole in the rubber.

 

I'm having this same prob and your follow-up is most helpful, thanks.

 

Just check the rod that holds the plastic lock if its completely straight (some bent parts too) or some plastic adhesive got caught on the rod. Also check the hole where the plastic lock goes through, things get lodged in there sometimes.
It would be good to have those TRIM REMOVAL KIT
this is very helpful prying those panels without damaging your trim and paint. Also if you have to do the headliner. Fast removal of plastic rivets.
I even use this tool to remove the A/C dash panel.
Also once you remove the front door panel, dont remove the rubber/metal seal. Leave it there even when replacing window regulator. Just slide the door panel inside moving up then align the topmost rivet and hit the panel to lock, then the rest will align well.