The window lift motor powers the window regulator to move or roll the window glass up and down. Overtime, the factory window lift motor can go bad and cause intermittent problems and fail completely on simple unwanted situations like being unable to close the window when it is raining, prevent you from reaching something without opening the door and more. If you are having problems rolling the window up or down but you can hear the motor and glass trying, the glass wont quiver then you may have a problem with your window lift motor.
Calibration of the automatic movement range of the window must be done after installation and can be done by holding the switch for 5 seconds upon rolling the window up and down the first time.