What are the symptoms of a faulty car electronic fan temperature control switch?
3 Answers
The symptom of a faulty car temperature control switch is that the electronic fan behind the radiator cannot function properly. The car's radiator is located at the front of the vehicle and can be seen by opening the engine hood. The function of the electronic fan behind the radiator: The electronic fan is controlled by a thermostat. When the water temperature rises to the upper limit, the thermostat connects the power supply, and the fan starts working. When the water temperature drops to the lower limit, the thermostat disconnects the power supply, and the fan stops working. Its function is to cool the engine radiator. Reasons why the electronic fan cannot work properly: Excessive internal dust causing poor heat dissipation. Dust can slow down the fan's rotation or cause fan failure, which can also affect the operation of the car radiator fan, so it should be checked regularly. How the car temperature control works: The temperature control switch has a bimetallic strip inside with different thermal expansion coefficients, which allows it to deform at a certain critical temperature range, causing the contacts to connect. When the power supply is reached, it returns to its initial state within this temperature range and cuts off the power supply.
A few days ago, I drove to the countryside and noticed the temperature gauge on the dashboard suddenly spiked to the red line, which was obviously abnormal. The weather was quite hot, but the cooling fan wasn’t moving at all—it didn’t even start. Sometimes, the opposite happened: the fan would run nonstop right after a cold engine start, wasting electricity and making noise like a faucet left on. This issue caused my car’s temperature to frequently rise, and the A/C cooling performance worsened, making the cabin uncomfortably hot. Fortunately, I pulled over in time to inspect and found out the thermostat switch was faulty—otherwise, engine overheating could have led to a catastrophic failure. I recommend everyone pay attention to the temperature gauge and fan behavior while driving. If anything seems off, get it fixed immediately to avoid a roadside breakdown.
The temperature control switch for the fan in my old car is broken. The most obvious symptoms are that the fan either keeps running wildly when the engine temperature is still normal, wasting fuel and being noisy, or it refuses to start when the temperature rises and it should kick in, causing the coolant temperature warning light to flicker. The air conditioning suffers as well, with significantly reduced cooling performance, making the car feel like a sauna. The reason is simple: the temperature control switch is supposed to activate the fan when the engine heats up to around 85 degrees, but now the sensor is faulty and doesn’t detect anything. When driving, I usually keep an eye on the temperature gauge and shut off the engine if I notice anything unusual, letting the car rest to avoid unnecessary strain from the fan. If left unchecked for a long time, engine overheating and damage could lead to repair costs high enough to buy a new car—so don’t underestimate this issue.
