Power windows have been an option on cars for many years, and while this feature is convenient, they are more prone to breaking than manual windows. The electrical components of power windows, from the wires and fuses to the motor, can break down and leave you with windows stuck open or closed. There are a few situations that can occur when the power mechanism is damaged or broken, and they each point to different causes.
For instance, when none of the windows are working and you don't even hear the motor running when you push the buttons, the fuse might have blown. Check your owner's manual to determine where the fuse for the windows is located. Remove the fuse with your fingers, or a pair of pliers if necessary, and check to see if the metal filament is broken or damaged.
However, bear in mind that a blown fuse is busted for a reason. There is likely either a short or a power overload in the power window circuit. After replacing the fuse, turn the car on and try to lower or raise one of the windows. If the fuse blows again, then you're looking at a wiring problem. If not, the power surge that blew the original fuse may have been a one time occurrence. This is especially common if you try to open a window that's frozen shut.
If the fuse is not at the root of the problem, you'll need to check the wiring, motor, relays and switches in the circuit for signs of damage. You will need a diagram of the electrical circuit for the power windows, which may be located in the owner's manual. Determine the location of the relay and check it with a test light to ensure it is receiving power. If there is no power output from the relay, check the wires connected to it. If they work, the relay will need to be replaced.
When only one window is not working, you will need to remove the door panel to inspect the power window system for that particular door. This typically involves removing lots of screws and washers. Be sure to store them in a dish or a bag so none are lost.
You should inspect the electrical components as well as the window's ability to move freely up and down. You may need to detach the window from the regulator that connects it to the electrical components. Once this is done, manually move the window up and down to ensure nothing is inhibiting its movement.
When you can hear the motor running, but the window won't budge, you could be looking at a faulty motor or damaged gears. The linkage and the crank mechanism or the steel cable (depending on the make and model of your vehicle) used to raise and lower the window could be rusted or broken, making it impossible for the glass to move. When a steel cable breaks, you'll likely need to replace the entire setup for that particular window.
If the window doesn't move and the motor isn't making a sound when you press the button, the switch, motor or wiring may be bad. Faulty wiring can often be determined by gently moving the harness that secures the wires between the door and the interior panel. Try to open or close the window while doing this, and if you get any response, then the wiring is likely the cause of the problem.