The problem of a constantly running refrigerator is easily diagnosed with the standard operation of the refrigerator part called the defrost timer. You don't even have to turn off your fridge to diagnose this one. 1. Simply find the knob that operates the timer and turn it until you hear the click. 2. Wait 22 minutes. 3. Check to insure that your refrigerator parts are working properly and the unit has come out of defrost mode and is back to normal operations. If your refrigerator parts are not in working order, and the machine is not out of the defrost cycle, you have a defective defrost timer which needs to be replaced.