Brief odd air noise in cab while on the interstate.

[Trevor73402]

This may be a known common thing, but being a new Ram 3500 owner, I’m not familiar with anything like this (Ford didn’t do it). While driving a couple hours on the interstate (AC on/recirculate), there was a noise like you’d hear when someone just cracks the window open a bit when you are driving at higher speed. Very noticeable “wind/air” noise. It lasted 30-45 seconds, then you could hear it begin to seal off…..then it was completely gone. This happened twice in 3.5-4 hours of driving. It’s like a vent door or actuator door opened for some reason and then closed back off. Any idea what this could be?

Any help is appreciated.

 

[dslbrnr]

It's probably opening the vent to allow fresh air into the cab. I think recirculate cancels/opens occassionally to allow oxygen in. Mine doe's that when switching from recirculate to fresh air, or visa versa

 

[jabartram]

Mine does the same thing 2020 Power Wagon, sound like it changes from recirc to fresh for a few seconds.

 

[Trevor73402]

Thank you all for the info. I had a feeling it might be something to do with fresh air.

 

[Firebird]

Normal, Rams have done this for years