Central locking problem

[Trifid]

Hello.

I am experiencing problems with the central locking on my Mk1 3 door 51 plate focus (pre facelift). I noticed the problem yesterday where if I open the car at the driver’s side (or with the remote central locking) only the driver’s door unlocks. If I then unlock the passenger door from inside and then try to lock it the driver’s side the central locking will lock the driver’s door and then unlock it. There is no attempt to lock the passenger. If I only unlock the driver’s side I can then lock it. However, I can both unlock and lock both doors from the passenger side. The boot opens through the remote on the key.

I’ve recently taken the door cards off to install new Speakers. Do you think something has come lose?

Thanks for the help. :)