To find out if it is short, measure the 3 wires with a three-phase connection one at a time with respect to the motor housing where there is no paint with the voltmeter or ammeter in continuity mode, in case this is grounded it will give you continuity and the motor will be so burned the same with the 3 wires Normally do not give continuity. To know if a coil is open to the same thing but now 3 measurements only with the 3 wires of the coils or three-phase connection in this case the three measures have to give you contiuity if there is no contiuity the coil is open and you have to rewind. I hope you understand me greetings