Fixed whistling wind noise with the flick of a switch....

[Crazy_Creek]

It could be just my rig. A 2005 Dodge Ram Dually with a 2013 Arctic Fox 865. At highway speeds of 65 to 70 I get this annoying whistling wind noise that seems to be coming from the rear doors or sliding window. I have just lived with it but it would sure be nice if I can make it go away. I just figured it was the nature of the beast....a barn door traveling a over a mile per minute.

Well...that is until I discovered a little secret.

Here in Florida, the air conditioning is running 10 months of the year and we travel out west in the summer so the same is true there. I keep the re-circulation button engaged to keep the humidity down and to keep out unwanted smells.

On the way back from a bow hunting trip in Alabama this weekend, I for some reason disengaged the re-circulation button and low and behold, the whistling went away. I thought to myself...no way. So I did it again, and again, and again....and sure enough every time I disengaged the re-circulation button the whistling went away.

I guess you learn something every day.

[tktplz]

bikerdib wrote:
My understanding, you are not supposed to run the vehicle on recirculate long term anyway. There is a small chance of carbon monoxide build up. It is intended to be used when there is high level of outside pollution (smoke or something like that) or for short term quick cool down then switched to outside air.

I run it on recirculate because I can't stand smelling the exhaust or even cigarettes of other drivers in front of me.

[billtex]

Recirculation also engages the compressor (at least on GM's) same as A/C and Defrost...could be a belt or compressor itself?

[bikerdib]

My understanding, you are not supposed to run the vehicle on recirculate long term anyway. There is a small chance of carbon monoxide build up. It is intended to be used when there is high level of outside pollution (smoke or something like that) or for short term quick cool down then switched to outside air.

[sabconsulting]

I've never been a fan of the recirculate switch. I prefer to get fresh outside air into the cab rather than keep re-breathing the same air, though I understand if it is really hot then the aircon is going to work a lot harder trying to continually cool outside air.

The back wall of my cab has a pair of hidden vents and I guess the Bernoulli principal causes a partial vacuum behind the cab and sucks air out through these vents, which, with the aircon set to recirculate, sucks air in through door seals and other places.

Steve.

[kohldad]

On the Dodge, by going to recirculation, you reduce the pressure in the cab ever so slightly.

My driver's door has some wind noise and gets a bit worse with a head wind. When it gets annoying, I switch to recirculate to jerry rig the problem.

The real solution is to have the top of the door adjusted in ever so slightly to apply a little more pressure against the gasket.

[profdant139]

Same thing happened on my Nissan Pathfinder. Turns out the passenger compartment air filters were clogged. I replaced them -- the noise was reduced but not perfect. I discovered that the flap that secured the filters in the slot was a little loose. Some duct tape on the flap, and voila! Silence.

[Bedlam]

I've read somewhere else that the rear door seals on the Dodge are the cause. By opening the vent (turning recirculation off), you allow pressure to stabilize and it does not try to escape through door seals.

[Raften]

Positive pressure or lack of would be my guess.