window stuck down?

Hi,
ford focus cc3 MK2 petrol 09
Drivers window will go down and up in small segments but if full down will not come back up.
I I disconnect the electric plugs that are on the door Panel ( small black box 4 inch X 4 inch ) I hear a lot of activity plug them back in and the windows goes up,but if sent down again it stays down, can you advise what is wrong.
many thanks for any help.