Passenger door not locking

[S-Type-Frank]

Just purchases x reg s type v6 and noticed passenger door not locking with remote or key ? It is now leaving all doors unlocked unless I deadlock it in which case passenger door remains unlocked but offers are locked. Does anyone know what to look for inside door trim and best way to remove ?

[volor]

Could well be that the solenoid on passenger door has become "lazy". This can be difficult to resolve without a new lock, however certainly would suggest a good squirt of WD40 in the 1st instance, followed by a good 10 mins of locking/unlocking. However the fact that you can only lock some of the doors using the deadlock function, could mean a new lock is in order. Try the cheap options 1st. Don`t exclude a squirt of electrical contact cleaner, if u have it before the WD 40.

I take it that u have checked there is no dirt in the lock mechanism?

[S-Type-Frank]

Yeah tried all that think its the lock just looking for one at the moment

Thanks for you reply