Air circulation not working

[Spike318]

The airco or heating is working. Al long i don t change the place where i want the air. The swich is on window and rear window. If i touch it switch it to feet or only front window. I hear a lot af air. But the air is not detectable on feet or middle or window. If i shut down the motor and restart after a few hour it is working. But when i touch the air postion switch. No air inside the car. Please help me