Air not coming out of vents, only defrost vent

About two weeks ago the air in my 96 stopped flowing out of the regular vents. I can hear the air working and I can feel cold air coming out of the defrost vent at the base of the windshield. Are there any fixes I can attempt myself?


Thanks

I was overseas in July and my wife said this happened to her. I found it to be a large vacuum leak on the rear selector switch. Replaced the switch problem gone. Good luck.

About two weeks ago the air in my 96 stopped flowing out of the regular vents. I can hear the air working and I can feel cold air coming out of the defrost vent at the base of the windshield. Are there any fixes I can attempt myself?


Thanks Just a heads up for those that have the same "defrost only" headache!
I see this was an older thread but after researching a few related threads of similar headaches with the winnie(s) I was able to fix my 96' GL 3.8L that of course once again went on the fritz!! In the Canadian climates, if you don't have al the heat source you can get, your sc______ed! I was only getting defrost at the front windshield no matter what setting I moved the control in the passenger compartment area. I found that the red hard plastic vacuum hose that snakes around behind the left front (passenger/ upper) manifold area had been rubbing against the refrigerant line going thru the firewall. I could literally feel the worn out section of this small hose and knew by the threads published on the topic I was going after it myself! Getting at it was no pleasure as the wipers air plenum cover and parts of the air intake plastic piping had to be unscrewed but in all took about 11/2 hour from start to finish. Once I got under there while pulling apart the rubber boots from the vacumn connections I found that I had broken one more grr....These parts are extremely brittle and lite force and a screwdriver tip to help persuad it made all the difference thereafter. I went to the wrecker and happened to find the piece I needed almost literally lying there (as the van bucked and farted, at idle, all the way there ) for $5.00 took me all of about ten minutes to get it plus a few extra hoses just incase I broke some more! I did happen to look at another Winnie in the bone yard and came across the exact hose problem that it had rubbed thru the hose and should be a "Ford recall" if I had something to say about it. I reinstalled and "voolah" I have a smooth running Winnie and can warm my toes up again.. Good luck to any and all that have this same problem by not being afraid to go at it yourself!

Head Bum and PumpitUp are right, the blend doors are vacuum operated and they are set up to default to the defrost position if vacuum is lost. In my case, it was the selector switch in the dash not allowing vacuum to pass back to the rear blend door (so mine was not a leak, per se). Thus, it was blowing hot air all of the time. It is fairly easy to remove and replace this switch.

But, as PumpItUp did, you can trace the vacuum lines through the firewall and under the dash to find where you are losing vacuum. If it is a large leak, you may get poor idle as PumpItUp describes.

BTW - when I did the lower intake repair, I broke this vacuum line assembly in the engine. The lines do seem to get brittle over time. Plus, it costs $130 to get a new one from Ford. Ouch. hard lesson learned.