jon, your radiator should have a temp sensor where the blanking plug is and you should also have a thermostat in your engine it looks as though some previous owner has had problems with overheating (probably the original temp sensor gone faulty) and decided the cheapest way would be to remove the sensor and thermostat but in the process they have disabled the engine cooling fan, check to make sure they haven't installed a manual switch somewhere to operate the cooling fan, or more likely they have had the engine cooling fan rigged to the AC switch which they used as the engine started to overheat.and it looks like the wires you have spare are indeed the wires for your engine temp sensor.