Air conditioning blows out of the defrost vents only

Not sure what year, make or model vehicle is in question, but the issue is due to an actuator that has gone bad. Sometimes referred to as a mode actuator or blend door actuator. This actuator controls where air/heat will blow from (defroster vent, forward vents, floor vents or combo, etc.). Good luck. Ron @ Speed-O-Repair.

check your fuses then the blend door motor

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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

defrost does not work it does not blow at the top windsheil

Sounds like the flap valve in your vent system that allows air to go to the defrosters is either jammed or broken. Unfortunately you will have to take the vent system apart to look.

First be sure that you do not have the controls set to defrost the windows since on just about all vehicles nowadays with the controls set that way the air conditioner will be turned on...even if it is not so warm outside. So...be sure that you do not have any of the controls set to defrost and that the heater is turned all the way on.

It sounds like though that the control for the vents is not operating properly. This is a combination of mechanical movements of the vent flaps and small "air motors" that operate the flaps. These air units are controlled by air vacuum taken from the engine compartment through tiny hoses. If the hoses get cracks, holes or come loose from their fittings then your vents will not move correctly so it is a matter of looking and tracing each one of the hoses to make sure they are fastened correctly, have not come loose and are not cracked or leaking. The problem can even be in the engine compartment where the hose(s) connect to the engine vacuum system...so it will take lots of looking carefully with flashlights etc....good luck.

It's normal for the A/C compressor to come on with the defroster to dehumidify the air so the windsheild won't fog up under humid conditions. You can still control the air temp. out the vents with the temp. select switch.

AC blows where you have your control switch set,if it only comes out your defroster have the vacuum check at the blend air doors or if you have a faulty heater control unit.

did you cheked if there is enough refrigrant ( freon ) in your tubes by measuring the pressure . if there is you may need to check your condensor its may be clogged and not letting enough air comes through to cool the refrigran

You probably have a vacuum leak on the passenger side. its a small plastic hose some times they come unpluged from the engine. or brake.