No Extra Coolant Temperature Port In Toad Engine

Usually these have a coolant temperature sensor screwed into the radiator itself. When a certain temperature is reached it grounds a relay circuit turning on the cooling fan. When air conditioning is called for, it activates the relay again causing the fan to run when the compressor clutch is engaged.
I would guess just a defective coolant sensor.
Usually there is another sensor screwed into the engine block somewhere that has to do with all the operating parameters of the engine control module.