Pro Air A/C unit on my new to me 2012 Merc Sprinter Van

[Tom Greenleaf]

Quality - What's that? You (customer) are the test lab.
BTW that probably has a sight glass on top unseen in your picture.
You read it like this look for better in color or videos as needed if unsure.
Crude basics like this,


This is read while operating at a raised idle,