Fridge too warm, evaporator icing up

After replacing the defrost heater, main board and thermistor I still had the same problem. Called a repair guy and he (with the help of GE on the phone) diagnosed that the temperature sensor was bad. So I ordered from partselect and installed it and it fixed the problem. Been good for a couple months (knocking on wood). To install I had to cut the 2 wires to the old sensor, crimp the 2 new wires on and snap the new sensor to the clip on the evaporator. Very easy. Make sure you seal the ends of the wire crimps so moisture doesn't get in and corrode the connection.