Have an 850 R that does not blow air to either side of lower foot compartment and to the rear. My feet are friggin frozen! Thought it was dashboard control unit but I switched one out with another functioning new one and still no air. Next to try actuator units, but can both sides and rear all fail simultaneously? Is there a relay switch for this unit? All other actuators work as does AC and blower etc. Any ideas? replacing actuators is tricky because its very tight in there. Hope is not lost yet.