stuck on defrost

[mikem]

i jsut purchased a 99 f-250 and i am stuck on defrost no matter if i am on vents or floor. i get heat and ac out of the defrost. everything seems to work okay just only comes out of the defrost. any solutions. i checked the electric vacum pump and i get vacum out of it, but i don't know how much i should be getting. help please.

mike

[robthebuilder]

You're on the right track... probably is a vac. problem. Open your glove box, squeeze the sides to allow the stops to get past the dash, so you can get behind the glove box- then you will find the vac. lines and the actuator. You might get lucky and find a loose vac. tube. If not, you probably have a bad actuator or selector valve. You'll figure it out, it's not too hard.

[Sting]

Where would i look on a E450? Same exact problem, stuck on defrost for everything AC and heat.