Passenger side central locking faul.

Greetings.

My passenger side door lock fails intermittently, will not lock/unlock via the remote or the button in the centre console.

I have read that the drivers side wiring loom is normally the cause of this as the control module is in the drivers door.

The confusing bit is that even when the passenger door lock isnt working I can hear the lock mechanism trying to work when I press the button (slight clicking when unlocked and a loud "grrrrn" noise when locked) but no movement of the lock itself.

This suggests that the lock is getting power but is somehow stuck.

I'm just after more experienced opinion please, before I investigate further.

Many thanks.

RR