I think from memory that the white and yellow disconnected wires are for the door lock key switch which normally operates the central locking relay. As standard, the drivers door does not have a locking motor at all, the lock is manually operated by the key and the the switch operates all the other doors power locks via the relay.
I`d guess yours has been fitted with remote central locking at some time and
the switch has been disabled.
Another posibility is that someone has fitted "five wire" lock motors to both front doors to allow central locking from from either front door.
Colin.