Henry H

I have a 2010 F150 4x4 Lariat with 5.4 liter engine. Out of the blue for some reason, the passenger side will only blow cold air. The truck does have the passenger preference switch so that the passenger can regulate their heat/cold on their side of the truck. I have tried to turn the passenger heat select switch on and off with no change. I have tried to turn the truck off in an effort to possibly re-set the system and then re-start the truck and I can only heat the driver side of the vehicle with the passenger side still blowing cold air. Any help out there with my problem that can lead to me fixing this situation or do I have to take the truck to a dealer to get the heating system looked at and possibly repaired. Many thanks in advance to anyone who has encountered this problem and fixed it themselves.

toledo

replace your blend door actuator.. its behind the radio.. theres a thread on the year specific section