YES, Mike is correct, the Sensor is simply a 10 K NTC Thermistor -- temperature-variable resistor.
In the OB RTS cables that I've seen (dark green ones), the Red and Green wires in the cable are connected together, as are the Black and Yellow ones, at the Thermistor. The OB hardware looks for a resistance change twix these two pairs of wires (by running a small current through the Thermistor, and looking for a voltage change vs temperature change)
At room temperature, the Thermistor should read close to 10 K Ohms.
The sequence of the wires from one side of the four-pin cable connector is, Yellow - Green - Red - Black. And, it should not make a difference which side of the connector that you start the above sequence, there is no polarity required, as the RTS is just a resistor.
IMO, FWIW, Good Luck, Vic
4/20/08: 18 Shell SQ 175-106 Vmpp, Stacked 5548 SW+, 1350 AH Surrette 4KS25's, MX-60, Kubota SQ-3250 25 KVA Polyphase Diesel genset. Thanks OutBack for this Forum + the great Support and Service.