So,
on my 300SDL it only blows air up to defrost the windshield. No matter what i press it never blows down to warm the feet. Not sure what that could be.
Also when I put the car in Drive it will start to idle rough, when i shift it into neutral it idles fine. Not sure if the system is sucking in air or not. Had a fuel leak that I just fixed but that didnt solve the problem.