On Monday, July 14, 2014 7:16:19 PM UTC-4, nestork wrote:
Hi again.



This fridge is equipped with a test plug.



According to the fridge's wiring diagram, measuring the resistance

between the orange wire of the test plug and the blue wire going to the

defrost timer will measure the resistance across the defrost heater. I

did that and measured 38.7 ohms. The factory spec is between 34.6 and

37.5, so it's a little out of range, but at least I know that the

defrost heater is in one piece.



According to the fridge's wiring diagram, measuring for continuity

between the orange wire of the test plug and the brown wire going to the

defrost timer will determine whether the defrost thermostat is making

the circuit to the defrost heater or breaking the circuit to the defrost

heater. I did that and got no continuity through the defrost

thermostat. So, the defrost thermostat is breaking the continuity to

the defrost heater.



That means that the defrost heater is good, but the defrost thermostat

isn't allowing any current through that heater, so I still could have a

block of ice around the evaporator coil.




Based on what you describe, it sounds to me all you're seeing is that
the defrost timer isn't at the point in time when it closes the switch
to turn the heat on. Which is what you'd expect to see, because it
only occurs a very small percentage of the time.