I have a fairly basic 12+ year old kenmore refrigerator with a top freezer. In the summer even though we have air conditioning, we have to turn the cold up on the dial in order for it to keep food in the refrigerator part cold. It then starts to freeze food in the back and on the top shelf. In the winter, we have to turn the cold back down on the dial and it still tends to freeze food on the top shelf and back of the shelves. The freezer seems to work fine. When I turn the temperature control up and down, the compressor turns on and off, so the thermostat appears to be working at least enough to recognize those changes. Any ideas?