My friend’s Magic Chef MCBR1020W refrigerator which is two years old is not defrosting. I pulled the panel in the back of the freezer to check the defrost heater and thermostat. Note that someone had this apart about nine months ago and I’m not sure they put things back together properly. The thermostat part (502413000036) is actually two parts: a defrost thermostat (DT) and a over-temperature fuse (OTF), two wires each, sharing a 4-wire connector. The connectors for this and for the heaters are in a 4 inch square plastic junction box with a cover in the upper right-hand corner above the evaporator coils. I found the OTF hanging by its wires below the junction box and in open space near the evaporator coils. I found the DT "inside" of the junction box and not on or near the evaporator coils.
It seems to me that if the defrost thermastat is inside of the box and isolated from the evaporator coils, that it would not necessarily be the same temperature as if mounted directly to the evaporator coil like most refrigerators and therefore may open (disable) the defrost circuit when it should be closed.
Can anyone tell me how should the DT for this particular Magic Chef model be properly installed?
Your defrost timer is in the back of the fridg, just turn it till the compressor stops, if no defrost, you either have a bad defrost thermostat, or a bad heater. If you get defrost, replace the defrost timer.