what would be a comon reason that cold outside air would not to come through the passanger air vents warm when dial is set to cold without the AC turned on.

Might have a stuck blend door, it open to the heater core so you'll get heat no matter what. Usually when a blend door gets stuck it's the actuator that goes bad.

Check the cable/actuator link between the right rear radio console and passenger footwell left wall. If all ok...and door isn't blocked by debris or a dead rodent (!), you may have to get used to the fact that even fresh air has to travel proximate to the closed-off area, and thus picks up some conducted heat. Hence fresh vented air is always a bit colder than outdoors ambient air, such that using the AC is required more often in the shoulder seasons. This is very common for many Subies.

blend door, white plastic arm under dash passenger side, push it forward (towards engine) and you'll have hot air! if not then check your fan, do you hear the fan turn on? if not, replace the fan. YouTube can tell you how to do that. If you do hear it but have no heat, check your coolant, park with the front of the car uphill as much as possible, the goal is to have your radiator cap above the rest of the cooling system, must be with a cold engine, check the gauge! Leave radiator cap off, start the car and add coolant as it goes down, don't run it like this forever, if that doesn't work... flush your heater core, disconnect the line (middle, behind engine, will be two hoses going into firewall) with LOW PRESSURE water, from a hose maybe DONT TURN FAUCET ALL THE WAY UP flush the heater core, then reconnect lines if that doesn't fix it then id replace heater core. YouTube should be able to help you with that.

Whoa...it's simply a stuck blend door! Sheesh....