Just wondering if it is normal when the heat is on with the selector on the legs/feet mode to randomly hear the actuator change inside the air box.

It’s almost like a blend door is randomly changing maybe to the windshield and back to the legs but I can’t say I feel a loss of air flow during this.

Any insight would be appreciated.

2015 f150 Crew.

Thanks

 

I was thinking along the lines of the air conditioning kicking in and out to keep moisture content down or the blend door opening and closing for outside air. I used to think it was the fan kicking up to a higher speed but its not. I don't feel any difference in air flow.

 

I felt that a lot in my 15 noticed it once in the 18.

 

I think that is the recirc blend to get the heat temperature up quicker, I've noticed it on high fan settings in the cold in all Ford vehicles.

 

Thanks guys. I was wondering if it was done on purpose. I noticed it more when the temps were in the single digits.

 

Yeah, mine does the same thing - it's definitely the redirec door - it would be nice if the button lit up once it changes though.

If you press the redirec button after you hear the noise difference you'll notice it will light up but make no sound difference (because it's already closed) - if you press it again it will open back up and sound like it did originally.

I think it closes it to get the truck warmer faster then goes back once it's warmed up.

The other day it closed automatically and I left it alone - 10 minutes later or so it went back to outside air once the truck warmed up more.