2016 F-150 XLT-HVAC system is putting out max heat all the time. Manually adjusting the heat control does nothing. Also, when in AC mode, same result; heat all the time. Blower motor seems to be OK and the actuator doors all seem to be working properly.

 

I actually have the same exact issue with my 23 lariat!! I haven't taken it in yet, but it's on the list. My wife first noticed it and I thought she was crazy at first, but nope. In my truck auto actually does a little better than manually setting the temp. Either way, good gosh its very hot unless it's on low or AC button is on. Insane.

 

You MAY have a fault in the outside temperature sensing circuit. If the wiring to the temperature sensor is broken (possibly chewed by rodents) or the sensor itself is faulty, the climate control MAY "think" that it's really cold outside and heat will be delivered. I had something similar happen on my car and discovered the wiring to the temperature sensor behind the front bumper was broken. It is a VERY fine wire maybe 28 gauge?

- Jack