2005 Yukon / AC blowing "weird"

[mountie]

My AC is nice and cold.
Blower is strong out of all vents.
Once in a while, the blower speed goes 'up and down'.
Could the windows open, be a cause?
Anyone have this issue before?

 

[Devlin]

Mine sometimes does this when it randomly goes from recirculation AC to outside air AC.

 

[mountie]

Mine sometimes does this when it randomly goes from recirculation AC to outside air AC.

Well, that's encouraging to hear.... Thanks for the response!!