Originally Posted by PAhonda

You can also try the caveman method on the non-working fan motor. Start the car, turn on the a/c, the tap the non-working fan motor with light/medium force with the handle of a screwdriver. See if the fan motor turns on. If the motor turns on, then the fan motor is likely worn out. The test light method will tell you if you are getting adequate power and ground to the fan motor.