The brick core thermocouple senses the temperature of the brick core. It is connected to the core thermocouple terminals on the processor control board. Location 47 (L47) indicates the current brick core temperature as sensed by the brick core thermocouple. To test this K-type thermocouple, read mV DC across the red and yellow thermocouple wires. Compare the mV DC reading to the K-Type Thermocouple Chart. To check for a short to ground, disconnect the thermocouple wires from the processor control board. The thermocouple leads must be greater than 20 meg ohms to ground when disconnected. If not, find and remove the short.
NOTE: The polarity of the thermocouple is extremely important! Make sure the red thermocouple wire (negative potential) is in the "R" terminal and the yellow wire (positive potential) is in the "Y" terminal on the lower two terminal block positions of the processor control board. Refer to the Internal Low Voltage Wiring Diagram for details.