Why Doesn't the Fan Turn On After Replacing the Coolant?
2 Answers
After replacing the coolant, the fan does not turn on because the vehicle's fan control sensor is set on the radiator. The fan will only operate once there is no air left in the pipes after replacing the coolant. Coolant is a type of liquid containing special additives, primarily used in liquid-cooled engine cooling systems. It has excellent properties such as preventing freezing in winter, boiling in summer, and protecting against scale and corrosion throughout the year. How to determine if the coolant is low: Observe the coolant warning light on the dashboard. If it lights up, it is likely due to low coolant levels, though it could also be caused by excessively high temperatures inside the cylinder. Check the coolant reservoir. If the liquid level is below the minimum mark (MIN), do not continue driving and add coolant promptly. Check the water level markings on the coolant bottle. The coolant level should normally be between the maximum and minimum marks. To determine if the coolant is low, check the markings. If the coolant is below the minimum mark, it indicates a low coolant level.
Last time after changing the coolant, I also encountered the issue of the fan not spinning, which was quite concerning. Later, I discovered that I forgot to tighten the air bleed screw when adding coolant, causing air to accumulate in the pipes and leading to inaccurate temperature sensor readings. Another possibility was accidentally loosening the fan's power connector while removing the radiator—these connectors may look sturdy but are actually quite delicate. Additionally, overfilling the coolant caused it to overflow and short-circuit the electric fan motor. Finally, I remembered to check the fuse box, and sure enough, a 20A fuse had blown. My suggestion is to first check all the connectors, then test the temperature sensor. If you don't have the tools, it's best to return to the repair shop for a recheck.
