OK so wanted to bring all up to speed on my AC issue. So I called a local RV service guy, who came to my place and serviced my AC.
SO he says that units coming from factory with a "light charge" is not uncommon. It is also very easy to diagnose. He puts a multimeter on the compressor to measure amps. Mine should be pulling 13.3; it was pulling 9.
He used a line tap that resembled what we use to use to tap a water line to get water to an ice maker, only higher quality. Put some 410 in it, and it was blowing 54 degrees in no time. No cutting, no braising.
Warrantied for a year, $135 and $50 was him coming to me. He said dealers don't advertise this as an option, and many AC's get replaced when all they need is a bit more Freon.
Which brings me to ask the question: other than AC sales...why are RV systems sealed, and not serviceable like our cars and homes????
