Mazda Miata Radiator Fan Switches!
The radiator fan switch activates or deactivates the radiator fan based on signals received from the coolant temperature sensor, or in some instances, has a temperature sensor built in. Some aftermarket switches can be designed to activate at lower temperatures than the OEM specification to provide better cooling.
If you notice your radiator fan is behaving erratically, or simply not coming on at all, the issue could be with the radiator fan switch. One of the easiest ways to test this is to disconnect the plug and short the two wires together (use a conductive material to bridge the two prongs, and take care to stay clear of the fan!!!). If the fan activates then the switch is almost certainly your issue!
Replacing the radiator fan switch will involve opening the cooling system. Best practice recommends draining the system below the level of the switch to avoid a mess, however this is not entirely necessary in all vehicles. Be sure to bleed the cooling system after servicing to prevent air from causing issues while the engine is operating!
We stock and sell a wide variety of quality Mazda Miata radiator fan switches from these manufacturers: