Buick Lesabre Window Regulators and motors were made in Mexico and were very good quality. They were originally designed so that you could replace the motor or regulator without changing out the entire assembly. If the regulator breaks you will hear a crunching, grinding sound and the glass may fall into the door. If the problem is the motor you may find the window does not move up or down at all. Sometimes the gear inside the motor strips out and you might hear a ratcheting sound 3-4 times as the window goes up or down. You can not change the gear on these, you would need to change the entire window motor. For the original parts it was possible to replace the motor or regulator alone.
Around 2002 GM started using a one piece assembly made by Kamco in Korea. These are terrible quality and sound like they are about to break even when new. It is necessary to change the entire assembly as one unit. This is one instance where the Taiwan replacement parts are actually better quality that the OEM parts. There are a few aftermarket brands of regulators for the Lesabre. The China made parts are very inexpensive. The Taiwan replacement are much better.
The switches are not a problem on this car. Power Up has changed a few door lock motors (door lock actuator) for the Lesabre but very few.
Want to try this yourself. Below link to our parts site.