2007 E70 AC switching vents on/off every few seconds

[rbryantaz]

Fellow E70ers,

I have searched a bit on this topic and saw several posts about low battery causing the system to switch to defrost but I charged the battery and am still having the issue which seems to be getting worse.

Previously if on any of the automatic controls it would switch air to the windsheild instead of the main vents after several minutes so I just always manually controlled the fan. Now it is much worse and only lasts 10 seconds or so before switching and then oscillates.

The driver side seems worse than the passenger side where the passenger still seems to get most of the air out of the main vent. It doesn't seem like a blower resistor because It sounds like the fan is still running but I don't feel much air flow (I don't really feel a lot of air from the defrost either but I still hear the fan running almost like it is blowing into a closed flap).

Could I have a weak actuator motor or something where it can't hold the flap in one place or is there some other cause for this?

Hopefully someone else has experienced this and has a fix.

Thanks,

Rich

[rbryantaz]

Note that the air always seems to be cold so it doesn't match other cases for people that had warm air out of one vent and simply needed a freon charge. I will double check the AC pressures but so far it doesn't appear that the freon charge is the issue.