I am not sure if this is the right place to ask this question, but I could not classify it a different way. My heater on my 97 F150 is acting strange. I think it is in the switch on the dash, because I can turn it to high heat and it heats for a minute or so, then starts to cool off. I can turn the temp button a few times then back to hot and it works for a minute or two then cools off again. Everytime I mess with the heat control button, it gets hot again?????? any ideas?

 

Your blend door acuator is bad