First obviously check the fuse, the legend will be symbolised on the rear of the glove box which needs dropping down to both see it and get to the box, the fuse box will be in the glovebox. (This is true of modern Fords but as yours is slightly older I should think it's a MK4 it may be different, the fusebox will most likely be under bonnet in this case)

If good then I would check the relay which will be located in same place, if this is good I would suspect the motor itself, very unlikely to be wiring problem.

The wires pass through corrogated rubber sleving into the hatch itself which will be near the hinges at the back.

Martin