Trane ACONT900AC43UA Service Manual page 195

Indoor Blower Motor
Figure 9
Step 4
Jumper 24 volts AC in to the blower motor low voltage
plug pin #3 and pin #4 (Figure 10) The blower motor
should start to run after a short delay. The blower
motor should run at 75% of its programmed torque.
Does the blower motor run?
Yes: Repair or replace the blower low voltage harness.
No: Replace the blower motor.
Figure 10
GF - H 5