my heat and air conditioner to 1 or 2 setting, there is a loud whistling sound? on 2005 Lexus GS300

but when I increase the setting to 3, 4 or 5 it stops, what might this indicate as a problem

Asked by for the 2005 Lexus GS300

Possible there is something in the vents or your blower motor bearing is showing signs of wear.

Hope this helps