Every couple of years the defrost thermostat goes in my unit. I think it went out again last night. I had the same problem as before, the circulation fan is in-op. I took the thermostat out, by passed the wiring and the fan came on and cooled the unit down. I went to Sears this afternoon to buy a new thermostat, put it in and it appears to be defective. In a round about way my question is should the thermostat have continuity when not installed?