Hmmmm. this morning on my travles I was paying close attention to the heat and flow-through, its NOT related to revs. When stationary no matter if the engine was at 800 or 3000 rpm the flow was the same, put it in gear get moving and suddenly improvment so I dont see it as an alternator problem (plus I dont have any other symptoms of a dying alt), perhapes something to do with vacume is that possible?. Just had a (bad) thought, maybe the blower is dying.
Mike.