heater only works all the way hot or all the way cold, what can it be?

There's ten different F-150 models for this year. What model do you have? Customer Concern: There is no temp control, it is stuck on full heat. This is a manual type system. Tests/Procedures: 1. Even though this is called a "manual climate control system", it is still electronic. The only difference is that the manual system is unable to output trouble codes. 2. Start out first with disconnecting the battery for 10 minutes and retest after hooking the battery back up. Sometimes the control head can freeze up but will work once rebooted. 3. If same, unplug the control head and using a 9 volt battery, jump power and ground to pins 6 Dark Blue/Light Green (DB/LG) and pin 7 Orange (OG). The motor should move in one direction. Reverse the polarity and the motor should move in the other direction. 4. If the motor does not move, check for a binding blend door and if OK, replace the actuator and retest operation.

blend door motor is bad. common failure for fords. Roy