WD1 is on when you have voltage at DA1, WD2 is in when you have voltage at DA2. To check the motor, unplug the leads, make sure neither read to ground, connect your meter across them reading resistance, rotate the motor a very small amount and stop until you get around several times. Every time the resistance reading settles it should be roughly the same resistance. If it’s ever very high, you have a problem. Make sure P150 doesn’t drop while running the motor. If it does, you may have a PY2 or PY4 board with no cap from P150 to G150 in the controller or a bad cap under the board. I kind of doubt it’s an encoder problem since the doors work in one direction and the encoder is just 2 optical switches.