I have a whirlpool arc 4000 and it has been having defrosting issues lately. If it is fully defrosted and turned back on it will work for a week or two before the fridge section will not feel cold as the freezer is frosted up.

To troubleshoot this i tested the continuity of the defrost thermostat and the defrost heater which both read 0. Also i bypassed the defrost thermostat by connecting a wire straight through it rather than the thermostat. However the fridge compressor does not stop and its still in cooling mode. Even if the heater was bad doesn't the fridge need to stop when in defrost mode. What can i do about this ?