1) Put a VOM meter or test light at junction block inside door panel where motor wires connect. That will tell you if you have juice to the motor) If you do: switches and wiring can be assumed to be OK.
2)Assuming you used the old motor, remove regulator (to eliminate track as problem) and apply 12v. directly to motor. If the motor doesn't spin, the motor is most likely at fault. Remove motor from assembly (be careful with worm gear)and wiggle armature out. There is a bushing at opposite end from gears with typically two oil access/drain plastic caps. Get some lube down in the bushing, line up the shaft of the armature with the bushing (a movable target) and reassemble(twist and wiggle with the gear, again)
3)Check plastic gear in gear box from motor to make sure it is not chewed up.
I repaired two regulators with frozen!! motors (beach cars) rather quickly with zero parts expense by lubing the bushing. I don't know what you are supposed to use for lubricant (I used sewing machine oil), but since the motor sits vertically, with bushing end down, I wasn't too worried. As always the Secretary will deny all knowledge of your mission.