The picture in reply #19 shows the diode anode (positive end) conected to one of the power busses but does not show the polarity of the bus (+ or -), if it's positive (+) then the diode is backward and causing a short circuit. What is the polarity of the bus the diode is plugged in to?
The silver band on the diode is the cathode (negative end) , should go to the positive side of the motor.