Hello Gents
I was working out on some detail on my 92 V12 after having sat for a couple of years unused, and noticed that when I try to lock the car from the driver's side, both doors respond but the co-driver's lock jumps back as if electrically actuated to do so and remains unlocked.
However if I lock the car from the passenger's side both locks function correctly, locking and unlocking.
Any idea what I should be looking for?
Thanks for any tips.

Cheers
Farouk

 

The actuating rods on the passenger side very likely need adjusting using their double ended turnbuckle-type adjusters. They are easily accessible under the door card.

 

Thank you Greg for yet again making my life easy
I pulled out the door card and tried to lock the car. I saw the lower rod in the first and second picture below where it is connected to the brass tube, presumably one of the adjusters? It moved towards the lock with the brass tube as well as the rest of the rod connected to the door lock, but at some point the rod and brass cylinder kept moving but not the rod connected to the lock. Looks like it has a spring inside.
I uncovered the poly black cover to see the amount of rust there (third photo) and suspected seizure, so cleaned it and sprayed it with WD 40, and lo and behold it was as good as new.
I sprayed any other moving metallic parts before reassembling the card. I decided to do the same thing for the other door as a precautionary matter.



Photo1

Photo 2

Photo 3


Thanks again buddy
Cheers

 

Good job! That brass adjuster is indeed sprung, done, I think, in order to soften the "clonk" on locking and unlocking.

I had a similare problem and solved it by deactivating the sprung bit in the brass adjuster. See post 19 on this link:
https://www.jaguarforums.com/forum/x...repair-177091/