Whirring sound from passenger side when heat is on

[Chupacabra]

Hi all,

First time post. I have a 2007 Yukon XL Denali that i bought used last year. I have fixed a couple small issues on it already (using the info from this forum).

The current issue is a whining/whirring sound from the passenger side when the heat is on and the fan control is turned all the way up or all the way down. Sometimes the noise gets louder when braking.

Just curious if anyone else has had this issue and has a solution for it?

Thanks!