Hvac blowing inconsistently

[Chopperslb]

I have a 2012 Ram 1500 4x4 with 5.7 hemi. During the winter the heat would blow hot, then switch to cold, then back to hot. All while the fan also blowing only on high. The fan would blow a little on the 3 lower settings but not much. Now in the summer the ac will blow cold on highest fan seeing, and periodically blow a little on the 3 lower fan settings. If I put it on Max air (recirculate) it will cycle from hit to cold inconsistently. I have already replaced the resistor, and the heater controls. Not sure what the next step is. Thanks for any help.

 

[TexasRed1970]

I have a 2011 with the 6.7. When the freon gets slightly low, ice will build up on the cooling core. Air will then not pass through the cooling core causing low volume of air from the vents. Turn the compressor off (A/C button) and leave the fan blowing with recirculate on. If the volume of air increases (takes a few minutes), this is what is happening with yours. After "defrost" sometimes the passenger will get some cold water dripping on their toes.

The fix is to have the freon recharged.