P4 Cascadia bunk ac compressor not turning on

I've noticed recently that the battery powered bunk ac of the truck isnt working. It's not blowing cold air and the compressor isnt turning on.

Usually when i turn the ac knob to highest temperature and then to cold, i can hear and feel the compressor turning on in the back. Now it's not doing anything. AC isnt blowing cold air either.

 

does anyone know some simple troubleshooting steps to check or have a copy of the service manual?

 

Another update: it does seem like the compressor fan is spinning, but it’s just a high pitch wining and not like how it was before.