grab your multimeter and hunt for 3 pairs of 2 and 1 group of 3wires having continuity on wye with delta there will be 3 groups of 3 leads having continuity, this only works on 9 lead motors but check a connection diagram for your specific motor
have your motor shop install rtds. You will be able to monitor each phase's temperature in real-time and also trend. btw, easa states that 1/32" of dust on the stator of a motor can raise the operating temperature by 10*C
