I had this problem, there should be a metal piece of wire between the solenoid and the actual lock, which is used only for the central locking.

When activated, it pushes the wire, which in turn pushes the lock down, so locked. When unlocking, it pulls the wire thus unlocking.

I bought an xr3i with this problem, any escort with central locking should have this piece of wire.

If you need more info send me a pm.