Why does my ac blow hot air? on 2001 Dodge Ram 1500

I checked and the low side shows 45psi after charging it. The compressor does kick in and is running. The low side line is cold to the touch also. The drain hose that comes out of the firewall is dripping like crazy when the ac is on. I did replace the heater core last winter also. Is it possible I messed something up when I did the heater core? I pulled the dashboard back off to make sure I didn't forget to reconnect a harness or vac line anywhere and all seems to be fine. I am stumped!!!

Asked by for the 2001 Dodge Ram 1500
Sounds likr the main HVAC blend door actuator is not switching the vent from heat to A/C. Need to observe if the vent door is moving when you switch the setting.
So it should move when I turn the temp hot to cold, or defrost to ac?
yes it should.