Coming back from a v.a. appointment today (interstate 77) I thought it was awful hot in my 2010 f 150. So, like anybody would do, I turned the temp. control down to half. A few minutes later I turned it all the way off... fan turned off by the way. A few minutes later, I rolled down my window....70 mph...25 degrees. I finally got cool but blew my wig sideways. O.K....fan off....temp control all the way off . So I tried the a.c....zip...still heat coming out of dash and floor ducts. Closed the dash ducts and by the time I got home my feet were sweaty. No unusual noises coming from dash, just hot air. Temp. gauge in normal range. The weather is supposed to be in the 20s and 30s for the next week or two so I can live with it for the time being.
Any suggestions ? Sound like a little fix or something I'll have to finance ?
Thanks in advance.
semper fi

 

With the fan in any speed but high, does it work?
if not, you need a new resistor
this is my 06 f 150, 2010 is similar
https://www.fordtruckzone.com/threads/fan-only-works-on-high-repair.658492/

 

Don't know. Will check that first thing in the a.m. Thanks for the tip.
semper fi

 

Dusty, its the door/flap that opens for heat and close for no heat. With truck cold this a.m. and engine off and blower off, ign. on, turned temp. control knob and could hear the flap open and close Went to Mcdees for my wifes muffin and left the flap closed. When temp. gauge said the eng. was warm turned on blower and it blew cold air...turned it to heat and bingo it thru hot air as it should. So, to see if the flap was working properly, I turned it back to cold. Bingo, cold air as it should. So, lets see what happens when I ask for heat. Turned knob back to the heat position and pfffffft, no heat. Get home , with her cold muffin, and shut engine off...ignition on, tried heat control knob and can no longer hear the flap open/close. Fan works as supposed to but flap doesn't react. Now instead of sweaty feet I've got an icy wig. Still sound like a resistor ? Flap hanging up maybe ?
Thank you
semper fi

 

Resistor is only for the fan
There is a vacuum line for the control.
I'll have to do some homework on that. I'll get back to you

 

THANKS Dusty. appreciate you taking the time. Next time I'm near your house I'll buy you a beer/pepsi.
semper fi

 

Dusty, don't know what to say....my truck healed itself. Put about 50 mi. on it today. A little warm, 55 deg. I varied from hot/cold/hot/cold...on/off. Tried the air, all o.k.
engine off, ign. on, could hear the door open and close probably 25 or 30 times. Thinking maybe the door was hung up ? we'll see.
Thanks for your time
semper fi

 

Still researching
Looking to see if the door is controlled like in my Town car, I think it is
Glad to hear it is mended, still looking for th cure for when it "misbehaves" again

 

When it fixes itself, it is typically a blend door issue. Seen it on both Ford and GM trucks.

 

Think it was just hung up. Is working fine now. Warm weather coming, glad I can shut off the heat now.
Thank you.
semper fi