750li 2006 dual control passenger side defroster light off and defroster not working; all else works

SOURCE: 2006 750li passenger defrost not working

BMW defroster works on vacumm so if you have air blowing from the dash vents when the seclector is on A/C and when on bi-leval the air comes out of the dash vents and the floor vents then you have a vacumm leak most likely a vacumm hose is off, Or due to the age of the car the engine heat causes the hoses to crack and break. the BMW V-8 engine has a problem with the rubber holder for the PCV valves cracking and leaking that causes very low vacumm pressure also check all of the vacumm lines that go through the fire wall most likely your problem is just a disconnected or broken vacumm hose or the PCV valve holders.