6560-423, Sensor with White Plug Connectors. For 505,601-605,and 624 Systems Only Do not use this sensor on 700 or 800 systems or newer 600, 600S systems. FOR BALBOA SYSTEMS ONLY! Resistance cannot be checked. The Temp Sensors are located in the filter compartment on the side. They are unscrewed from the inside of the tub and the wire is fed through the tub into the equipment compartment. Follow the wire to the PC Board. To feed the new sensor, we usually drain the tub below the hole and pull the old sensor out a couple of feet into the tub, cutting the old sensor head off, we tie on the new sensor (connector end) to the old wire and pull the wire through into the equipment compartment. The connectors on the Temp Sensor are attached to a pc board connector that is located on the PC Board (usually at the top). There are other wires connected to this plug: Jumper interlock wire,Flow Switch, High Limit and Temp sensor. Remove the pin connector from the board .