140 Degrees in the middle of winter

That’s the outside air temperature according to my 05’ F150 (Lariat with the 5.4 v8). This started as reading a little high (15-30 degrees), but we’ve moved on to differences over 100 degrees. This morning it was 8 degrees, yet the truck read 140. This is a problem because evidently this is hooked into HVAC computer and when I want heat it sends me outside air, after all its 140 degrees! Thank god for Bun warmers. So I’m too cheap to go to the dealer, any suggestions about what is malfunctioning and where it is?

The ambient air temperature sensor is the main suspect. When it gets damaged it will cause any number of erroneous info inputs. It’s usually located just above the black box on the vertical metal support at the center of the radiator and just in front of it. It has a wiring connector attached to it.