My 2003 Ford Expedition a/c blows out the defrost vents and will not blow out the dash vents

COULD BE BLOWER MOTOR OR RESISTER

Failed HVAC Blend Door Motors under the dash

Vacuum leak under the dashboard, probably at the automatic brake release.

blower door assembly under dash is broke or resistor burnt out that controls it

I had the AC problem too, and they said there was a hole in the hose. They fixed it and now it comes out of the vents as it suppose too, but when I first accelerate to go up a hill, it stops blowing out of the dash vents. Once I have stopped going up the hill, the air starts blowing out again. Weird.

check or replace the blower relay, located under the dash panel RH side.

My 2003 EB had the same issue, until I took it to my local dealer. There is a TSB that calls for this part to be replaced.You need the following part number: 2L1Z19C828AA - HOS ASY-A/C VAC

Hope I was avle to help, glad you up and going.

It does sound like a vacuum problem. Check vacuum hoses under the hood especially to vacuum reservoir cannister. Sounds like a hose is loose or leaking.

You either have a bad control, or motor running the air direction door in the front HVAC unit, or a door that is stuck.

The front and rear units are totally separate.

The door directs where the air, cold or hot, should come out, whether it is panel vents, floor, defrost, or any combination of those.

This door and motor are located inside the heater box which usually requires a lot of the vehicle dash assembly to be taken apart to get to these parts.