A/c blows thru defroster - 2001 Mercury Mountaineer

mode door stuck or failed

Suspect a defective blend door actuator motor that controls airflow for the defrost. This electric motor may be defective and in some makes and models can be extremely difficult/expensive laborwise to replace

i believe your question is my escalade is only blowing air thru the defrost ports is that correct

These selections are run by Engine vacuum. sounds lie a diaphragm is NG to control the lower door

the actuator to the defrost door is inop. try running the climate system thru all the modes ac heat defrost vent off etc, maybe it will begin operating . look for any vacuum leaks

look for a vacuum leak going to the control head

bad vac. line

Does this only with ac setting?
Reason I ask is if it is blowing thru the defroster vents then you have a vacuum leak.Defroster is the default postion(no vacuum).
If it does it when ever you turn on the heater or ac it would most likely be a leak in the supply line(small black vacuum line) that is under the hood and runs thru the firewall at the heat core area. If it only does it when you set the ac then it will be one of the blend doors under the dash leaking most likely.

your a/c and heater blow thru the defrost ( top of dash? ) and the vents. Or defrost/or the vents.? and not on the floor? Well all of these should work. can you hear the motor inside the dash turning to they're perspective spots on the dial the motor pulls a cable and closes or opens appropriate doors as the selector switch is moved. if not the switch may be faulty. and you can get it from a parts store or dealership. CK the parts store's first they will be cheaper and will be able to give you a look at what needs to be done to replace it. But it can be done on most "fine " cars in 20- 30 min with minimal hand tools.

hi, seem you have vacuum problem,open your hood look for your vacuum distributor maybe have disconnected vacuum hose,ty