First welcome aboard.
We had a Nova Kool (Never Cool) in our current boat. It wouldn’t cool well so I pulled it out of the cabinet to see if it would work out of the cabinet with more air around it. Lack of cooling air flow around the back is a very common problem. So after I pulled it out it didn’t cool at all. I had a troubleshooting flowchart for it and I started checking it out. But when I ohmed the compressor it was out of specs so I called them to ask. Their answering system said they do not help customers troubleshoot problems but to call an authorized service center. On their website they list over 20 near me. I called every one of them. None would work on a freon based refer, only ammonia based for RVs. I ended up cutting off the coils, compressor and everything on the back in order to get it out of the cabin. We ordered an Isotherm refer that fit through the door. It cools almost too well. Unfortunately when we threw out the old refer I deleted the troubleshooting chart, but if you google it you can probably find it.