Order of operation for rooftop rv - Dometic Rooftop RV Air Conditioner

SOURCE: How to put refrigerant in Demotic RV Rooftop Air Conditioner

You will need to add a self tapping port to the suction side of the unit. You will have to determine what the size of the pipe is and then go to a local a/c supply company and buy one. It's kind of like a self tapping supply for water but for high pressure. Hope this helps. I would also put one in on the high side as well so you don't blow the valve in the compressor if you over charge it or the system is dirty.