Car radiator fans are absolutely essential for keeping your engine cool. They are activated when the temperature gets too hot and automatically disabled when the correct temperature is reached. In the case of a car radiator fan failing, the engine can quickly overheat, potentially leading to serious damage and even resulting in the complete write-off of an engine. Hence, it is not a car part that can be neglected under any circumstances.
It is very easy to see and hear when car radiator fans fail. The first sign will be the vehicle running unusually hot, the second sign normally being steam rising from under the hood. In most cases, however, it is very noticeable that the sound of the fan kicking in at regular intervals has stopped. In the case of car radiator fans failing, the vehicle should be stopped immediately and allowed to cool. On especially hot days the risk of overheating occurring and damage being done to the engine runs even higher. It is, however, still possible to drive the vehicle to a mechanic if a constant speed is maintained and moving air able to cool the engine.
In the case of a car radiator fan failing, the problem is often not specifically with the fan itself, which is a simple mechanism and has a long lifespan. It can be the thermostat that has failed, which prevents the fan mechanism from kicking in. In both cases the problem is not especially costly and is generally simple to solve, with most DIY mechanics able to do the job in a short space of time. Note that different model cars require specific parts. Contact a mechanic for more information.