What are the reasons for high radiator temperature but the fan not working?
3 Answers
The reasons for high radiator temperature but the fan not working are: 1. Electrical failure; 2. Thermostat switch malfunction. The method to check the radiator water level is: 1. Open the radiator cap; 2. There are scale lines and markings on the radiator, just check directly. The steps to add water to the car radiator are: 1. Turn the pressure cap counterclockwise to open it; 2. Fill the coolant to the scale line position; 3. Tighten the pressure cap and ensure it is fully seated. The function of the car radiator: Absorb the heat from the engine block to prevent engine overheating and malfunctions. Precautions for using the car radiator: 1. Prevent the radiator temperature from getting too high; 2. Replace the coolant regularly; 3. Do not use tap water as a substitute for coolant; 4. Choose high-quality diluted water or antifreeze when selecting radiator fluid; 5. Perform regular anti-rust treatment on the radiator; 6. Address radiator malfunctions promptly to avoid causing other issues due to continued use.
I've seen many cases where the coolant temperature is high but the fan doesn't work. The root cause usually lies in the electrical control system. The most common issue is a blown fuse - since the fan is electrically powered, once the fuse burns out, the power supply is cut off and the fan naturally stops working. Relay failure is also quite common; when the component responsible for switching the power supply fails, the signal can't get through. Additionally, a faulty temperature sensor is another major cause - if the sensor can't detect the rising water temperature, it won't command the fan to start. A broken fan motor or short/open circuits in the wiring can also lead to the same problem. If left unaddressed, engine overheating can cause severe damage, potentially cracking the cylinder head, skyrocketing repair costs, or even total vehicle write-off. I've seen many cases in repair shops where owners ignored this seemingly minor issue only to face major overhauls later. I recommend first checking the fuse location yourself - open the hood and look for the fuse box. If you're inexperienced, it's best to have it checked at a professional shop. Don't risk driving to save money.
The soaring water temperature with the fan not working points to a core issue of electronic system failure. The temperature sensor is crucial—it detects water temperature and sends signals to the ECU, which then activates the fan; if the sensor malfunctions, the fan won't operate. The fan motor itself might be burnt out or jammed, especially in summer when dust accumulates at the air intake. Additionally, a faulty relay or corroded wiring connections can interrupt the circuit. Modern vehicles feature smart controls, but software bugs can also cause failures. I always recommend using the OBD port to read fault codes for quick problem identification. Delaying repairs can lead to engine overheating, potentially melting piston rings and doubling repair costs. During routine maintenance, remember to clear dust from the fan area to maintain efficient cooling and extend vehicle lifespan.
