Prepare your semi truck to be Ready for the Road Ahead , with the Horton 3-Way Fan Clutch Solenoid Valve Kit that seamlessly engages the fan clutch. By working alongside the ECU, this replacement valve is able to detect when an engine's temperature rises above a certain level, allowing the solenoid to activate the fan clutch and engage a cooling fan. Built with a robust construction for reliable performance in harsh environments. FleetPride is your First Click in Heavy Duty .