Why doesn't air blow out dash vents? - 2007 Nissan Titan LE

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

There is a blend door acuator which moves when u change your settings. Its a electric motor. Down under dash, Will need a mech and a heating and cooling diagram to find where the motor is,

Might be the heater control. Where you change the position of the air.

It sounds like a vacuum leak not pulling doors under dash to where you want the air to blow.

the directional for defrost and dash panel may have gone bad,there is no fuse for this. under the dash on the main vent,you will see a little box/with an electrical plug in. it's called an acuator.when you turn the knob to defrost,or dash,the acuator turns the door on the main vent to let the air flow to either the defrost,or dash.your acuator is most likely your problem.there is only one plug in to it and only 2-3 screws that remove it frome the vent panel under the dash.thank you for choosing fixya.com!

Yes, you have a vacuum line that has come off, cracked or broke somewere under your hood. It's possible under dash vacuum diaphragm could be bad, but not likley....hope this helps you??

if you can hear the fan motor running strong, then you have to get behind the dash and readjust the vent adjusting control valves behind the dash, common to old cars the vent tend to fail and when adjusting the vent direction unit fail. being 1991 it will be cables or vacuum line. no book from any automotive store really go into removing dash fixing ac ventilation unit. is a simple fix, but time consuming once you get the dash apart you will be able to identify the problems.

Is it a new vehicle? I had a new vehicle that had the same problem. Answer was that the holes weren't punched out of the vent.

sounds like you have a vacuum problem

common problem, check under dash by the gas pedal if control arms are muving went selecting from ac to heat cuz this it is the control for the vents to go from ac to heat and to defrost.