Hi folks,
 
SW20 1992, central locking.  My drivers side door lock can only be operated manually (from inside via the manual switch or outside via a key).  When I use the central locking button the passenger side operates fine, and in fact the drivers side will unlock just but will not lock.  The mechanism moves a little bit but seems like it doesn't have the grunt to push it cleanly between unlocked and locked.  
 
Passenger side operates with a decisive movement.
 
I have the door trim off at the moment, have liberally used WD40 on the mechanism near the door latch and as yet no difference.  It doesn't seem to be an issue with the wiring in the accordion loom between car and door.
 
Any tips on what I can do to fix this or is it just the lock actuator or whatever it is giving up the ghost and needing replacement?  That looks awkward :(
 
Thanks!

Hi Firthy, I had the same thing happen to me and found that the manual locking latch (the small rotating switch right beside the interior door handle) was not progressing far enough so that the mechanism could not operate properly. So have a look at this rotating switch see if it is catching or that its travels its full length.

Thanks Ken, good suggestion. It does move fine when done by hand but as you say that could just be using more force. I'll have a closer look at it and see what happens. Cheers

I'm thinking I probably just need to take the locking mechanism out and give it a good clean.

Bumpidy bump..
 
I notice there are two different sets of parts for this - with and without 'anti theft', and then either power or manual.  Anyone know what these differences mean?
 
http://www.lithiatoyotaparts.com/parts/1992/TOYOTA/MR2/?siteid=215542&vehicleid=1276859&section=BODY%20HARDWARE&group=DOOR&subgroup=HARDWARE&component=Lock
 

I dont know what the difference is but I have a spare door that will have that bit still in it.

Cheers mate - I might take you up on that.  I'd just need to test it to make sure it suits etc.  Drivers side yeah?  Mine has two powered connectors through to the loom - one controls the central locking bit, and I haven't been able to work out what the other one controls.  I'll take some photos and maybe a video of it moving and see.
 

yeah its drivers side. I didnt pay much attention to it but im sure it has two connections as well