this is what i've gathered from around the threads, and it worked perfectly for me to save $150 in mechanics labor and self diagnose the problem.
if you heard a crack, and you window slid all the way to the bottom and is sitting there, it's probably one of the plastic clips that attaches the regulator to the slide (the horizontal bars) metal piece that physically holds the window
if you want to check if this is the case it takes 5 minutes, just undo the 2 screws from the door cover and carefully pry the door cover off starting at the bottom left hand side. i think there are 4 clips you will need to pop out and it can take a bit of force. once it's lose, lean it towards you and disconnect the wire clips (they will stand out). put the door cover aside, you will need it later.
then you should see two black hole covers in pretty much the middle of the door. remove these and move the window up with your hand until you see two metal clamps holding the base of the window. make sure they are attached to a plastic clip that is guiding them up the slide. if they are not, then your clip is broken.
if you want to know if the wire needs to be replaced you'll have to take the whole regulator panel thing off which is another kettle of fish. I'm probably going to attempt it at some stage when i get parts and there's a lot of good stuff on here from an older thread even though it's for a different purpose
How do I remove the inner door skin?Hope it helps
rooster