How a Window Regulator Works
A window regulator is a component inside the door of your car, which operates the up and down motion associated with electric windows. As they are highly used and abused parts of a vehicle it is more common for the drivers’ side regulator to fail first.
The system is comprised of the electric motor, which is that part located inside the door. There are "spur gears" and one "worm" gear which together create the correct torque level required to lower and raise your window. When you push the electric button to engage window movement the relay sends a signal to the motor. The motor then operates on a linear basis to create the up and down motion.
The motor receives the signal and it breaks a circuit to the gears which then spring into action depending on the direction you have selected for the button to move the window. Some issues with over-use of such button will result in a miscommunication between the relay and the motor, so that when you push the window button, the window will not move. It is then your task to determine whether it is the relay switch or the motor which is causing the problem.