The Hard Way, taking it apart, but are Ur Vent Motors working??? Is there a vacuum leak to them or cable not adjusted properly causing the problem???

Is the airflow the same whether its blowing hot or cold air? Are you getting more hot air than cold air when the AC is running? It might be a valve.

I am having sort of the same problem. The AC works for about the first 30-45 mintues of any cold start. Then, the AC reverts, and stops blowing through the vents. I can still here it blowing somewhere, just very VERY little come out through the front/cabin vents. I have checked to see if it comes out of the defrost or feet vents, and it does not. I took to a mechanic and he was stumped. Any help will be appreciated.

Funny U bring it up. This weekend my son in law came over to finish his '85 Ford LTD but was too late! Out here in the middle of the Sonoran Desert, we have "Pack Rats" that will eat ur wiring to SHREDS!!! Well, I had just re-wired & plumbed all the vacuum lines last week, when a Rat moved in! I found the bad wires & repaired them, but when Chris started the car & turned on the A.C. ALL HELL BROKE LOSE!!! Chris dove out of the car as Cactus went flying Everywhere in a big Dust Cloud!!! He filled a grocery bag full of both dried & Fresh Red Cactus!!! He got into it by going through the "Glove Box" (remove Door) and then having access through the vent housing. It was after about an hour of hand picking that he could try the fan again. When he did the "Resistor Bank" blew it's safety thermal device. So I had to "Silver Solder" all the corroded crimped coil wires to their terminals & used a piece of "Zip Cord" to replace the "Safety Device". Chris used everything long we had but finally got it cleaned out & working. U must push or "Blow" it backwards & work the "Diverter Valve Door" using "Mirrors" to see inside. Use Only Silver Solder as unlike Electronic Solder, it sticks to Ni-Chrome Wire Coils & won't get soft or corrode. John