No fan pressure thru vents on hot setting,but blows really ******* cold setting,blend door seem to operate,gets really cold in it below 20 degrees outside,windows fog up..Anybody know of this problem? have taken out cabin filters-no better

Great question dustin but the A/C is suppose to come on in defrost or mix mode- this is floor & defrost. Does not seem to make sense does it. One of the things the a/c does is remove the moisture from the air. You need warm DRY air to remove the moisture from the windows. An automotive H.V.A.C. ( Heating,Ventilation,Air conditioning) first forces air thru the a/c evaporator core then thru the heater core and out the selected vent. If you only want a/c a blend door will by-pass the heater core which is controlled by a hot/cold knob or digital temp cotrol on the dash. Now back to the cold air problem- assuming the basics are all ok- Coolant is full, Engine gets up to proper operating temp-around 195 degrees- upper radiator should be hot. Both heater hoses should be hot. If thats all OK the blend door might not be working. It is controlled by an electric motor called a Blend Door Actuator which are prone to fail. I have replaced many on ford vehicles. Hope this helps

Several things.
If the heater hoses are hot, the problem could be a blend door under the dash. The blend doors direct air thru the heater core and out the vents.

If both heater hoses are hot, and the radiator is full of coolant, it may be a blend door problem under the dash.
The blend doors direct air thru the heater core and out thru the vents.
It may still be under Ford warranty.

The resistor controls fan speed, not temp.
If the heat comes and goes, it could be the thermostat, or the radiator could be low on coolant, or have air pockets, or one of the blend doors may not be working correctly.
The blend doors direct air thru the heater core and the vents.

Is the gauge showing the engine is warming up to normal temp ?
Are the heater hoses getting hot ?
If the heater core is getting hot, it could be a blend door problem. The blend doors direct air thru the heater core and the ac evaporator among other things.

Usually a sign of a faulty blend door under the dash.
The blend doors direct air thru the ac and heater core along with the upper and lower vents.

Common question on this site. On late model cars, the vents are controlled by blend door motors. Small electric motors open and close doors to direct air flow.
Chances are you have a blend door that is stuck or a failed motor.
The default position is the defrost to make sure the windshield is always clear.
Someone will need to look behind the dash to see if all of the doors will move on demand.

The blend door is inside the box where the air flows from outside into the car. The air goes through the air conditioner first, then it goes to the blend door. When the door is open, the air will then go thru the heater and get hot. When the door is closed, the cold air will come out the vents. In this way, the blend door controls how much air goes thru the heater. When you are running the A/C, you want the blend door closed. If your a/c compressor is working but you are not getting cold air, the blend door may be stuck open.
My book shows your blend door is behind the glove box. It also says your door is controlled by a cable. What you should do is look behind the glove box to see what happens when you change the temperature on the panel. It should move a cable behind the glove box that turns a lever on the door. The cable should turn the lever as far as it will go. If it doesn't do that, it is either broken or needs to be adjusted. It may have slipped out of it's clamp. To adjust, loosen the clamp, turn the knob to cold, and push the door fully closed, then tighten the clamp.

Let me know if it doesn't look like what I'm saying or if you have other questions.

The hot/cold switch is probably bad.you have a blend door box that opens to let the cold air in and closes to let the hot air in.From what you are saying this part is no responding to the switch movement.Make sure power is at the switch and power should go through the switch when put on cold air this moves the blend door.Some times the blend door goes bad and has to be replaced its under the dash on the right side.

try changing the thermostat if thats not it check and see if you have water leaking in the passenger side floor board if so then you need a new heater core