I have a Kenmore 25353324302 that the automatic defrost stopped working on. I replaced the Defrost Thermostat the Defrost Heater, and the adaptive control board and wire harness. The fridge still isn't going into defrost mode automatically, but I can force it into defrost mode by pressing the door light button a few times fast. When I do this, the defrost heater comes for awhile, the ice melts and the fridge goes back into regular mode. Why isn't it going into defrost mode automatically? Is there something I'm missing?