The winch cannot be weighed: the electric engine runs, the shaft runs, but the gypsy is still although the brake belt is loose.

Possible causes: 
1.1 The gypsy is not closed on the clutch cones and slips under the load effect, or for some 
       reason the closing wheel is at end stroke. Check out all pieces in sequence.
1.2 The clutch cones or the gypsy cones are deformed and the clutch
       hubs are in contact and prevent closure.

1.1 Check out clutch tightening. If necessary, measure the parts and check out possible 
      deformations. It is possible to add some thickness to stem the problem. Then replace the 
      damaged parts.
1.2 Replace the clutch and/or the gypsy