Does anyone know what is causing my 2012 fusion to make a whistling sound when the ac is on normal ( ac doesn't have to be on just blowing out the vents) but when I turn on recirculation mode the whistling stops
Check your cabin filters for cleanliness and that they are properly installed.
You called it!
Sounds like there’s some sort of restriction try cycling from fresh air to recirculating a few times back and forth to see if it changes. If a door is not opening or closing completely in the heater box in this case the fresh air door it can cUse a whistle noise as the air passes over
When I had this happen, it turned out to be leaves (and other debris) stuck in the fresh air ducts to the cabin air filter.
Ofcourse, you could always try to just whistle back..
Ofcourse, you could always try to just whistle back.. 😆
If it only whistles while the recirculation mode is off, clean the inlet air vents, you may have some leaves,...
I just changed the cabin air filter a month ago where else could the leaves be stuck
The grills under the wiper blades.
It was the cabin air filter door not pushed in enough
Thanks for posting back with the fix.