how to fix year 2000 town car diver window

One of three things is occuring: 1--faulty switch 2--faulty motor 3--binding regulator I'm guessing on motor with a chance of regulator. The door panel must come off and circuit testing must be done to see if the motor is getting power and has ground. Then, you have to verify there is no physical entaglement of the regulator cable and gears. Good luck.