Refrigerator fan running all the time
The fan on this model is supposed to run whenever it’s plugged into the wall thermostat the relay etc. do not control the fan motor operation.
The real question here is whether the refrigerator is keeping the proper temperatures in each compartment, and the compressor should shut off periodically, you may not see frost on the evaporator especially the humidity is fairly low.
What are the temperatures in the refrigerator and freezer section currently.
John L.