My defroster is working. I can see the RPM's jump and hear the compressor cycle on and off. Plus it works really fast to clear the frost and water. I always use the defrost setting, never defrost and floor, and the temp is always set to the hottest when I use it. THe temp switch is working, because the air coming out of the defrost is really hot, and if I want cooler air while it's on vent, it works also. I still don't know what is going on, but it hasn't done it in the last two days.
