Hi Chris_81 ... I considered the same thing .. just cutting out the fuse ... but also considered it is there for a reason (even though there are 2) The reason is likely to protect from "over heating the area for prolonged times as the heater gets pretty hot.
This is why I asked in one my earlier posts (#33) for the parameters or specs for the fuse so it can be replaced without having to purchase an entire Fan Evap. assembly.
I am going to call Whirlpool again to see if they can give specs on the 2 Thermo-Fuses.
Maybe too early to tell, but any update on whether replacing the fan motor / Thermo-fuse solved your icing issue? I am literally going through the same thing with the same model, though I did witness my defrost heater doing it's job while the coil was one block of ice, then subsequently not heating once there was only a smaller chunk of ice (though still covering the thermistor). Not sure if it wasnt cold enough to run the heating cycle, or maybe I overheated the thermofuse with the heat gun? Either way, if it freezes up, I'll definitly check this.
Did you hear back from Whirlpool? Might be tough prying specs on subcomponents from their fists.