2001 f150 5.4 blows hot air

[brunsze]

My truck for the last year has been stuck blowing hot hot air and no matter if i turn temp control knob..i figured it was blend door and didn't want to fuss with it but today it started blowing cool air and wen i turnt the temp control knob it would go hot to cold but wen on cold it would cut out every now and then and blow hot air ..any ideas? I just replaced pcv valve maybe 2 day ago..idk if it has anything to do with it or not but also when it first started doing it i ran seafoam thru the vac system and it would operate normal for a day or two?

[RhinoZ24]

My truck for the last year has been stuck blowing hot hot air and no matter if i turn temp control knob..i figured it was blend door and didn't want to fuss with it but today it started blowing cool air and wen i turnt the temp control knob it would go hot to cold but wen on cold it would cut out every now and then and blow hot air ..any ideas? I just replaced pcv valve maybe 2 day ago..idk if it has anything to do with it or not but also when it first started doing it i ran seafoam thru the vac system and it would operate normal for a day or two?

First off don't use seafoam again, especially not in your vac lines. It's not a miracle cure like the people at the autoparts stores claim. It can do serious damage if you use too much or do it a lot. Just a tip lol. PCV (Positive Crankcase Ventilation) has nothing to do with your HVAC system as it just ventilates the unburned fuel from your crankcase so your oil isn't fouled up and your engine doesn't blow up.

Your issue sounds like either the blend doors as you listed or your HVAC controls on your dashboard could be going bad, particularly the temperature control switch. I know on my '05 the air will randomly turn on sometimes and I have to turn the switch on and off again for it to stop so your air cutting out and switching from hot to cold could be the same thing, the switches.