Hey guys needs your help my wifes 89 f150 5.0 wont blow heat out of any of the vents. I pulled the cover off where the heater core is and checked the door its working and you can feel the heat coming off the core. But when I put the cover back on no hot air blows out the vents. Please help its starting to get cold and I hate the cold and so does she.

 

Sounds like the blend door isnt working properly. How did you verify that it is working?


When a similar deal happened with my truck, there was a piece of plastic broken and wedged in the blend door so the door worked, but stayed open far enough that the heat wouldnt fully get to where it was going.

 

Check all vac. lines I had a similar issue but it was cold are defaulting to defrost Most of the vac. lines are under hood on passenger side and go into truck near glove box.