I had this very same issue in my 2012 Bighorn, fortunately it happened in the warranty time frame, La Mesa Sanford repaired the unit by changing the cooling unit,I am sure the cost would have been considerable, however the Technician stated that he did m
not believe the Cooling Unit was bad, he stated that the Manufacture had not used sufficient Thermal Transfer Jell between the cooling unit and the refrigerator, which stands to reason as the unit worked well for the first three months. See if you can technician that will do/examine this issue for you.