Ge WR50X45 Defrost Thermostat OEM Part

Replaced the de-frost timer because I noticed that one of the terminals was discolored indicating a high resistance connection. In addition I inspected the de-frost heater elements for continuity and shorts and they checked out OK. Then we come to the thermostat.....in the model ZIS48D with the mechanical de-frost timer there are two thermostats which are both the same part number (the digital defrost model only has 1 thermostat) The de-frost thermostat has a pink & an orange wire and the second thermostat is a fan delay thermostat and has a red and orange wire connected to it. When the fridge switches into a de-frost cycle the heater is turned on and starts to de-frost (heat) the evaporator. As the thermostat connected to the evaporator warms up the contacts open and cause the evaporator fan to stop. After the de-frost cycle the compressor switches on and refrigerant cycles through the evaporator cooling it down such that the thermostat eventually closes and once again switches on the evaporator fan. My fridge has now been running very nicely for about a week now and has therefore cycled through several de-frosts and seems to be working fine.

À new defrost thermostat

Bought the part from Appliance Parts Pro and watched the video you provided showing step by step how to replace and it was easy to replace.

I called GE service and they did very little to test what was causing the problem. Instead, he indicated the damper was bad and the part was no longer available and I would need to replace. I purchased a defrost timer and defrost thermostat and replaced both. I am keeping my fingers crossed as now two nearly two weeks later it is working fine. This saved me plenty as a new unit can run $6k to $10K

I replaced the defrost thermostat.