Digital Thermatic Fan Switch 1/4in NPT Sensor

The Digital Thermatic Fan Switch 1/4in NPT Sensor by Davies Craig is a precision engine cooling controller designed for vehicles requiring intelligent fan management. Whether you're running a classic hot rod, modern performance build, or heavy-duty application, this adjustable digital fan controller eliminates parasitic drag from mechanical fans by engaging cooling only when engine temperature demands it. The 1/4 inch NPT sensor threads directly into your engine block or radiator housing, providing real-time temperature monitoring and trigger-point accuracy that carbureted, EFI, and supercharged engines depend on for optimal thermal management.

This unit operates across a 104–230 degree Fahrenheit activation range, allowing you to fine-tune when your single or dual electric fans engage based on your specific cooling requirements and driving conditions. The 40-amp relay accommodates most aftermarket electric fan setups, from single high-output fans to dual-fan configurations common in custom chassis and street rods. Digital activation ensures repeatable trigger points without the hunting and cycling associated with mechanical switches, reducing electrical stress on your vehicle's battery and alternator while maintaining consistent engine temperature within your target window. The compact sensor design and standard 1/4 inch NPT thread pattern integrate seamlessly into existing cooling systems without requiring custom fabrication or adapter hardware.

This controller benefits anyone who has upgraded to electric cooling fans or operates a vehicle in high-heat environments—road racing, desert cruising, towing, or stop-and-go traffic scenarios where traditional belt-driven fans cannot respond quickly enough. Installation requires basic mechanical skill: identify an appropriate NPT port on your engine or radiator, thread in the temperature sensor, and run the relay harness to your fan motor(s) and ignition source. The Digital Thermatic Fan Switch works across carbureted and fuel-injected platforms, making it ideal for restomod projects, LS swaps, and any custom build prioritizing thermal efficiency and electrical simplicity. Verify your fan's amperage rating falls within the 40-amp relay capacity before installation.