Derale 16797 PWM Fan Controller Flush Surface Mount Sending unit.

PWM Fan Controller, Flush surface mount sending unit. Derale Performance is changing the rules of engine temperature control with Smart Technology brought to your car's cooling system through Derale's New Digital PWM Fan Controller. Historically, cooling fans run at 100%, even when less airflow is needed, constantly turning on and off as the engine temperature changes. This REACTION based temperature control system causes constant amperage spikes, excessive noise and premature wear. The Derale PWM fan controller continuously monitors your engine's temperature, therefore CONTROLLING the temperature and increasing the vehicles cooling efficiency, while reducing the amps used to do so. Here's how it works PWM Fan Controller, Flush surface mount sending unit.