The power windows in today’s cars are generally reliability, but something will go wrong once in a while. There are several things that can cause a power window to not open or close, but the most common is a faulty actuator/motor or a bad set of connections to that motor. Be sure to test connections and circuits before settling on the actuator or regulator being the problem.
To begin with, getting to the power window assembly requires access through the door. Removing the door trim panel, water shield, and so forth is different for each vehicle. In the main, hardware such as the interior door latch handle must be removed and plastic rivets around the edges of the panel will need to be popped. Most door liners lift off in one piece. You may need to unplug some things, such as the power window controls, door lock controls, etc. Removal allows access to the power window assembly through the door frame.
If possible, roll the window glass all the way up or lift/push it up and tape it into place in the “closed” (up) position. This allows full access to the regulator, motor/actuator, etc. Once it’s up, secure it with cut-to-fit dowels or boards at either edge. Disconnect the negative battery cable from the car’s battery. Then disconnect the plug/harness from the window motor. Using a meter, test all of the circuits from the window acuator to the button/lever controls (usually mounted on the door liner). Test the circuit from there to the fuse box. Then re-connect the battery and test for power at the fuse. If all is OK, disconnect the negative battery cable again.
Removal of the actuator/motor and regulator requires the removal of either screws or rivets. Usually rivets. On some models, the motor can be removed separately from the regulator. If so, tie the electrical harness away from the workign area in the door (use electrical tape) and remove the motor from the door. You can test the motor’s function if you wish. The regulator is easy to test as it is purely mechanical. If the window is all the way up and the regulator is still attached to it, then the regulator is likely still good. You can remove the tape securing the window and move the glass up and down within the frame to see the regulator’s movement.
Putting the new actuator/motor and/or regulator in place is the reverse of the removal process. Most replacement kits come with replacement rivets as well, but if not, you’ll need to have those in order to put the new unit(s) in. Now is also a good time to clean out the door’s interior and clear any drain holes in the bottom of the door. If these are plugged, it’s quite possible that your problem was due to moisture accumulation in the door causing a short in the motor or switches.
Once the new unit is in place, remove the items securing the glass and plug everything back in. Test it to make sure it works, including tets of other accessories such as power door locks. If everything works, put the door panel back into place.