Adjustable Electric Fan Controller Thread-In Prb

The Adjustable Electric Fan Controller Thread-In Prb from PROFORM is a precision thermal management device designed for engine cooling systems that require automatic fan activation based on coolant temperature. Built for street rods, muscle cars, custom hot rods, and performance vehicles, this controller eliminates the need for mechanical fan clutches by delivering dependable electric fan engagement at precisely calibrated temperature thresholds. Its thread-in probe design integrates seamlessly into existing coolant passages, making it an ideal retrofit solution for builders modernizing vintage cooling systems or optimizing factory setups.

This adjustable controller features a 3/8 inch NPT temperature sensor probe that monitors coolant temperature across a 150–240 degree Fahrenheit activation range, allowing you to dial in optimal fan engagement for your specific engine and cooling demands. The integrated 30-amp relay provides robust electrical switching capacity, enabling reliable control of high-draw electric fan motors without auxiliary relays or complex wiring. The adjustable design means you're not locked into a single activation temperature—you can fine-tune the setpoint to match your engine's thermal characteristics, preventing overcooling while ensuring aggressive cooling when needed during highway or track driving.

Engine builders, hot rod enthusiasts, and performance tuners benefit most from this controller's compact form factor and straightforward installation into any coolant manifold or block with 3/8 inch NPT threading. It works with single or dual electric fan setups, making it versatile across many applications—from small-block Chevys to big-block builds and modern swaps. The 30-amp relay capacity handles most aftermarket electric fan combinations, and the adjustable activation window gives you the control needed to optimize both cooling efficiency and fuel economy on custom vehicles where factory solutions fall short.