2012 Jeep Liberty. No matter what direction I set the blower, I only get air out the windshield window vents to defrost... any ideas

check the actuator motor or motors on the heater. It is inside on the base of the heater and directs the air where you want.

Sounds like a VAC. Line came off or is cracked, a vacuum leak causes the heater to go into default mode( defrost ) for safety reasons...

OK. So the blower notor isn't operating. Do you have power to the blower motor? The resistor is new from what I got. If you don't have power to the blower motor, then check the speed control switch and fuses. If you have power at the blower motor, replace the blower motor

check for anything that may have fallen into defrost vent poss jammed air blend doors.

THe blend door seems to be stuck. When you change settings from defrost to floor air or, vent, the blend door opens and closes directing the air to the place you want it to go to. I have had some success spraying a lubricating oil such as WD40 under the dash on the blend door. You need to get under the dash with a flashlight to locate it. It looks like a flap. Spray it with a couple of shots of the WD40. Go easy on the spraying as you may be inhaling the fumes. Keep the doors and windows open to minimize the fumes. Wait about 1/2 hour and try the A/C functions. (defrost, floor, vent air)

Not really a solution but, check that blend door in heater box is operating and that a/c drain hose is not plugged. (if there is ice in there, it may take a while to clear it out)

i assume you mean out the defroster. you have a vacuum leak going to the control head or a bad control head

check your heater core

the system defaults to defrost mode. you have lost vacuum look under the hood and find the vacuum line going into the firewall should be on the right side will probably find it has come loose or is cracked

it needs service,
i guess front glass defrost fails.
and 2 things must work , AC and the defrost damper
or #3 (overloads the function)
my heater core bad and leaking.(or its 2 hoses)