AC Clutch Not Engaging

I have 2017 5700XE with rotor dial AC/Heater controls. Hope I can get some direction what to try next. Few months ago I replaced my AC compressor (old one was worn out and leaking at the shaft). Pulled the vacuum and filled the system with 3.88 lbs, everything seemed ok. Being that it’s winter i didn’t use it much other than occasional defrost and few times I ended up in SOCal.

Few weeks back I was sitting at the truckstop near Phoenix, AZ and suddenly AC stopped cooling (blue light on). Basically AC compressor clutch not engaging. I carry a manifold gauge with me and immediately hooked it up suspecting low refrigerant pressure. To my surprise both high and low sides equalized to about 62 psi. Bobtailed to a local dealer and bought new pressure switch, still no dice.

If I jump the clutch to battery it turns on and system works beautifully. Occasionally the clutch would engage for 10-15 seconds and turn off again for few minutes. When it does turn on by itself I’m getting solid 14v on AC clutch harness. While the compressor is running the low side is reading 32psi, high side 130psi. Very sporadic as if some sensor is being tripped.

I have laptop with DDDL but cannot find any AC related read outs. Am I missing something? Is there a low pressure switch if so where would it be located (already replaced high pressure). Am I missing something?

 

It seems operational, I can turn the dial for air blender and flow and it seems to function as before. What should I test? Is there specific pin/wire for the blue AC on/off switch?

The symptoms are very similar to low refrigerant conditions although it is not. That’s why I replaced the pressure switch immediately. Is there another sensor somewhere I’m not seeing? I have two pressure switches on the high side pipe coming out of compressor, AC fan clutch and the pressure switch both been replaced and are functioning.