1993 850 GLT Central Locking problems.

[Chaz]

Greetings, great forum, I've been gathering fixes for my newly acquired 850 but I couldn't find a specific one for this problem, a few near it but anyway, here's the thing:

Central Locking. The key can lock or unlock either front door. Remaining doors must be locked or unlocked manually. This means from inside as the buttons can't be pulled up.
The alarm has been turned off as I think it was misbehaving. I don't need or want an alarm but I wonder if it's connected to the central locking problem.
The glovebox has been mangled and I also wonder if this was done in the same connection, in some misguided attempt to access the keyless remote relay that I think resides behind the glovebox?
I think maybe there's a central locking relay behind the boot pull?
When I turn the key in the driver's door I can hear a small click in the rear driver's side door.
I suspect it's just a contact cleaning issue but which contacts or where they may be leaves me in the dark.
Any help to just get a central locking feature working off the key would be most welcome.

I haven't yet seen how the door liners are removed on these cars either , any references have assumed this knowledge. If this is required could you please tell me how to do this without breaking something?
Thanks guys,
Chaz