Your switch is good, the fuse is good and they are working correctly. At the dash, the black wire (from the fuse) feeds the switch. Power comes out of the switch as RED or ORANGE (for Hi & LO speeds).
The short BLACK WIRE ON THE MOTOR goes to ground through a bullet connector, to complete the motor's electrical path. I suspect this BLACK wire is not bonded to ground properly. Either the bullet connector is not right or the wire is loose to ground. - Dave