2005 X5 4.4L - Has new thermostat, auxiliary water pump is working (although when I put the test light on it - it gets power for 4 seconds and then no power for 20 seconds then repeats cycle) (Also have access to a 2001 X5 3L that does the same thing) Blower fan works fine.
Once at 12 o'clock operating temperature, when at idle, the blower blows cool air only. If I rev it above 1500 rpm I get hot air. Seems that if I put blower speed to half power I get hotter air than if I have it at full speed.