I have an 01 S60 and the rear drivers side window will not roll down. At first was thinking the switch was just out (or maybe wishful thinking), but when I try to roll down with the front driver's side master switches the window still does not roll down, but there is still a clicking coming from the front dash when I press the switch. Does anyone know if this is a sure fire motor or window regulator problem?

 

you need to remove the door panel, to see whats going on in there.

 

Most likely the regulator. You can try tapping the lower side portion of the door panel lightly with a soft rubber mallet to see if it will make it function. But be careful because you may be able to get it to go down once, but not go back up. Those switches rarely ever fail.