Almost all modern vehicles rely upon electric cooling fans to pull air through the vehicle radiator to keep the engine cool. These cooling fans rely upon electric motor, and they typically have a moderate to high slow draw, which means that they are commonly controlled with a relay. That relay controls the fans for the engine. You want all of the parameters to be properly met so that everything works in tandem with the other components. The relay will typically be activated once the temperature approaches a high level. If you have a faulty cooling fan relay, …