headlights dim

The headlights dimming is probably just normal. When you use your power windows, you put a fairly heavy load on your vehicle's electrical system. Those motors take a lot of amperage to go up and down. Although it can be a sign of power window motor wear and tear causing excessive power draws to operate your windows, chances are things are working as they should. A good practice to help prolong the life of any power window motor is to regularly lubricate the window runs - the rubber strips at the side of the window that guides the glass up and down in the correct channel. When these strips of rubber and felt get dry, they slow down the windows and cause the motors to work extra hard. Lubricating these runs will cause the windows to travel up and down quicker and reduces the amperage draw which reduces strain and wear on the motors.