2.5 days, 2600 mile round trip. Early in the return trip it started getting warm in the cab. With the fan all the way up, blower going like hell, there was very little air coming from the vents. I spent an hour like that and knowing I had 15 hours of driving left I pulled over at a rest stop expecting to pull a broken recirc door off of the top of the blower motor.

So I pull the glovebox and drop the motor but the recirc door is just fine. Start the truck up to check recirc operation and the blower is working fine again. The problem never came back....any ideas what caused it? Air was cold, just very little of it so not the blend door either, I assume. Restart fixed it...I'm stumped.

 

Check the A/C charge. You may be low and the evap froze up on you.

 

I believe Spooler is correct. I experienced this a few years ago and the evaporator was frozen over. I had the system evacuated and recharged and have not had any trouble since.