Customer Questions and Answers for Defrost Thermostat (Bi-Metal) by Whirlpool

Tom, Temperature has nothing to do with the voltage. There should be 120 VAC into and through the entire circuit. (unless the defrost thermostat is an open circuit, due to it being warm). There should be 120 VAC into the thermostat on the blue wire, out of the thermostat on the white wire, into the heater, through the heater and at the yellow wire out of the heater to the defrost timer, as long as the temperature control is a "closed" circuit and the refrigerator is cooling. With the voltages you posted, there's a loose connection or damaged wire in the harness. The neutral portion of the circuit is accomplished through the yellow wire(terminal 2) and white wire(terminal 1). Do all of the voltage checks to chassis ground, on all the connections, this will verify wether you have a loose connection, or and issue in the neutral circuit at the timer. Thanks