I have a 2007 FJ cruiser and a year ago the air would only come through the defrost selection. No other selections will allow the air to come out which I think means the doors of the system are not changing when selected. Anytime the selector is in any other position than defrost it makes a humming noise and especially after shutting the vehicle off or turning it on. Any ideas? I had to manually adjust the blower so it would blow on feet and defrost. I think it's the motor but do not know the part number. Thank you for your direction.