Hi Folks,

Some time ago the comb flap actuator on my S4 failed and the practical solution was to simply isolate. I thought about simply wedging the flap open but would like to replace the actuator [my footwell flap actuator also failed and I wired the flap open after isolating the vacuum line].

Questions:

1. Why does the comb flap exist?
2. Anybody managed to replace the actuator without removing half the cockpit? If, so, hoe did you get at the actuator? Looks as though the centre console has to come out if not more.
3. Any body any bright suggestions on how to wedge it open [is it possible to wire the linkage open if it can be got at some how].

Thanks and regards
Fred R
Oman

The comb flap is there to blend the air mixture. With the flap open you should notice that air coming out of the bottom of the vent can be warmer than air coming out of the top of the vent. This is because the air flow on the bottom is the air that passes over the heater core and the air on top is coming from outside the car. The comb acts as a blend when trying to create the proper temperature so that you don't feel two separate air flows at different temperatures coming through the vent. I manipulated mine into the open position by taking apart the actuator and simply putting a rubber spacer behind the diaphragm to keep it open. I then plugged the vacuum line so that there would not be a leak at this point.

Eric van Tassel