Front Defrost does not work?

Found this on floor driver's side.

That is the top of the old-style mode lever. GM made the early ones like a skeleton and the gear piece likes to snap off. The newer ones are shown in the image next to the old ones. Your La Crosse must be an early build as they switched to the newer part in late 11 on most units. They are not fun to replace on most of them, the location is at the top of the stack. I have changed them by removing the trim panel under the dash and jamming an arm up into the dash to reach it. You have to remove the mode cam and actuator then replace both of the arms. If you cannot reach them from underneath, then you will need to remove the instrument cluster cover and the instrument cluster to get in through the top of the dash. Most of the panels are clipped in place. I would suggest getting the subscription to Mitchell at eautorepair.net FYI if you get that you can always print the pages to pdf to have them later.