We have a 2012 Sprinter by Keystone.277RLS. The bulb was out in the refrigerator. I checked the fuse and the fuss was not blown. I was going to have the bulb tested at a hardware store. We ended up calling an RV Technician in our area. He called us back. He told us to go outside of the camper and pull the black cover off behind the refrigerator. He said there should be two fuses in that box. He said the fuses could be blown or loose. We checked the fuses and the one fuse was loose. We tighten up the fuse and now the refrigerator works.