Whistle in Recirculation AC Mode

[dcarbs]

Highway speeds in recirculation mode I hear a whistle in my 2019 Silverado WT. Turn recirculation off and it goes away, turn it back on and the whistle is back. Anyone else?

[kevinwmsn]

Do you have one of the vents partially closed?  I had that issue on my Sierra because the a/c blows too cold at times even in the South.

[dcarbs]

7 minutes ago, kevinwmsn said:

Do you have one of the vents partially closed?  I had that issue on my Sierra because the a/c blows too cold at times even in the South.

Unfortunately I don’t. I double checked to make sure all were fully open.