Ok bricksters, this is the problem of the year: I have always noticed that every now and then, for no apparent reason, when using just the air vent positions (recirculated air off and temp at bottom, no a/c) the air flow would drop to nothing for a few seconds and then return to normal. At first I thought it was a pressure build up in the cabin but opening the rear window didn't affect it. Then, just last week a hint appeared. On a long high speed trip with the a/c on I was using the air vent (since the blower motor howls like a banshee) and same as always, every now and then the air flow stopped. But this time I noticed a correlation with the turbo boost gauge. At any boost above 1 atmosphere (bar) the air vent would close resulting in no air flow. As soon as the boost dropped below 1 bar it came back on. Why??? Quoting the king of Siam, "This is a puzzlement".

i rmn & etc.. Jim A.