[dmire44]

From start in hot weather, AC vent air doesn't feel cool. After driving a few miles, the cab starts to cool down and air from vents feels cool. This happens whether in recirculating mode or AC. I suspect outside air is overpowering AC air until it cools down. Maybe air door stuck or hinge broken?

 

[philipat]

Mine gets ice cold, but it takes a few minutes to get there. If it's cool, but not cold, and the air is flowing, it probably needs to have the refrigerant recharged. A shop can also check your system at the same time to ensure that you don't have any leaks.

 

[Primus]

When the temperatures and/or humidity get high, the A/C system has a hard time with cooling down the cabs, and can be especially true with the A/C charge low. The blend door would not have any effect unless the coldest setting isn't selected or is on defrost.