I hope you have better luck than I did in 9 years, with a Dometic RM2354 that was replaced twice by the previous pwner, once by me & almost a second time until I realized;
I wasn't the problem. Dometic is.
Did the other unit fail?
Do you have Solar?
Have you ever considered the DC Compressor version fridges out there?
2005 Roadtrek Versatile 190-a super modified & efficient Lifted Rig with a reconfigured Battery Box with 2 x 225ah Lifeline AGM 6 Volt Batteries, 250 watts Solar, a Victron BMV712 Smart Meter, Victron MTTP 30/100 Smart Solar Controller, a Magnum MMS1012 Inverter Charger & OEM Onan Generator. Plus more ...