Hot air

[old911doc]

After finding fragments of foam blowing out of my vents, I removed the heater box (no small task!) to repair the metal 'doors' inside. I laid a layer of fiberglass on each side of each door, and after it cured trimmed it to the edges of the metal. After the dash was reassembled and the A/C vacuumed and filled and coolant refilled, now I only get heated air out of all the vents, at any settings on the A/C controller. When the A/C is set on max cooling, the air exiting the ducts is 125 F when the ambient temperature is 80F.
Scanning with Durametric revealed no 'codes' in the A/C system. Interestingly, during the test cycle as Durametric controls the various stepper motors, there is cold air out the ducts for a fleeting moment, about 20 seconds, before the outflowing air becomes hot again. The refrigerant pressures are 38 psi low side, 250 psi high side. When I look under the heater box, the two stepper motors I can see move with commands, and their plastic pushrods are connected. The recirculation door moves normally. All the wires I can see appear in solid connection.
Any suggestions what might be the cause of only heated air from the A/C system, before I take the whole thing apart down to the firewall again?