My 2001 Ram 2500 series air conditioning is not blowing cold air. The compressor is working and the clutch does engage. I checked the freon and that is fine. The air conditioning lines are cold when the air is on, but its blowing hot air. The fuses are all intact. I remember always hearing a loud thump, like a vent door is closing, when the air condition switch was turned on. Now I don't hear that. Got any sugestions?

 

Not trying to be rude but is the temp dial turned all the way to "cold?"

Other than that, it sounds like the mixing door inside the heater core/blower housing inside the cab is stuck.

 

Can You Gain Access To The Vent Without Tearing Apart The Dash?

 

IF the charge is ok and psi's look "normal" the next place to look is to see if the temp door is moving full cycle. The actuator is right above where your left foot would be if you were sitting in the passenger seat mounted on the bottom of the HVAC housing. Roll the carpet back, hack up the insulation pad to access the two phillips screws. Remove the front one, loosen the rear one (tricky part) until you can pull the actuator down. There is a plastic adapter that mates the actuator to the temp door. Often I'll find that adapter cracked and it has to be replaced. If it is ok, and you can move the door by hand full travel (you can turn it and here it "thump" against the stops) you may have a weak actuator.