It needs replaced - bearings are out of it.
it is the blend door in the duct system
it possible is the blower motor is going bad or the blower motor squirl cage is rubbing Most likely there is debri in the blower motor cage, usually mice get in there.
Blower motor is going bad. They are usually behind glove box area.
The bearings are out of it. Replace Blower motor.
If the heater blower has humming noise when motor is running, first check its capacitor. If the capacitor is fine, then the motor is the problem and may need to be replaced.
If the noise is a squeaking sound, it could be coming from the bearings in the blower fan. It could also be coming from a worn bushing or bearing in the blower motor.
a mouse has built a nest in the the blower cage
Maybe a bad bearing in fan motor
Probably the heater blower motor.
Blower motor is bad
Bearing in blower motor?
it sounds like the compressor drive belt is loose under the hood.or the noise may be the blower motor{blower that pushes air into your car} rule blower motor out by using fan in heat mode. Or maybe a bearing in the clutch has gone out.