PeachParts Mercedes-Benz Forum - View Single Post - Air Flow Problem- Cold air out defrost heat out floor.

Graplr · #6 12-20-2008, 10:25 AM

That is interesting Brian. How did the faulty pump affect the monovalve? Shouldn't the air flow temp be independant of the monovalve since I get warm air, just not out all vents?

When I first purchased the car, it had a faulty aux pump. I just took it out and put an elbow in. This past week I finally put a new one in and manually wired it (not to the CCU system so I could see what difference if any it makes).

My findings were that it did not affect any air flow anywhere. But it did get the air warmer faster and did keep it warm at idle whereas before the air would cool at idle.

It is quite a substantial difference between the temp of the air coming out the defrost when an arrow button is depressed. I don't recall putting my thermometer in there (I usually keep it in the side vent and check the floor periodically), but I would guess around 50F when the floor is around 80-90F.