What to Do When the Tiguan's Fan Keeps Running?

[LeJayce]

Tiguan fan continuous operation solutions are as follows: 1. Insufficient coolant causing engine overheating, leading to continuous operation of the electric fan. The solution is to add antifreeze. 2. Radiator leakage causing engine overheating, leading to continuous operation of the electric fan. The solution is to replace or repair the radiator. 3. Thermostat failure, preventing water from being sent to the radiator even when the temperature reaches the baseline, causing engine overheating and continuous operation of the electric fan. The solution is to replace the thermostat. Methods to determine the condition of the electric fan are as follows: 1. Visual Inspection: Observe the fan motor's ventilation port for any signs of burnt coils. If there are burnt marks, it indicates the fan motor coils are burnt and cannot be used. 2. Smell Test: Use your nose to detect any burnt smell from the fan motor, such as burnt coil smell, burnt plastic smell (capacitor), or burnt wire smell (wiring). If any burnt smell is detected, replace the fan motor, wiring, and capacitor. 3. Touch Test: Manually check the fan's operation by turning the shaft. If it feels stiff or not smooth, it indicates lack of lubrication in the internal bearings or rotor scraping. If scraping is found, lubricate and clean, and replace the bearings on both sides to eliminate the scraping. Check the surface temperature; if it rises too quickly or too high, it indicates a short circuit in the fan motor, and the fan motor needs to be replaced.

[LeEliza]

My Tiguan also had the issue of the fan running continuously last week. Upon inspection, I found the coolant was nearly empty. Later, I discovered a small crack in the radiator was leaking, causing insufficient cooling and the fan to run wildly. I suggest you first check the coolant level when the engine is cold. If it's low, top it up with some purified water as an emergency measure. Remember to feel the temperature difference between the upper and lower radiator hoses—if the upper hose is hot and the lower one is cold, the thermostat might be stuck. If that doesn’t solve it, check the fan connector for any signs of burning, which is quite common in Volkswagen cars. Lastly, a reminder: the fan does frequently cycle on and off when the AC is running in summer, but if it keeps running for more than five minutes after parking, there’s definitely a problem. It’s safer to take it to a repair shop to read the fault codes.

[Edwards]

Having repaired German cars for over a decade, I can say that 90% of constant fan operation cases are cooling system related. Just two days ago, a Touareg owner had the same issue with non-stop fan operation - turned out to be a faulty coolant temperature sensor reporting 120°C when actual temperature was only 50°C. Also check if your radiator fins are clogged with poplar or willow catkins (they can form a felt-like blockage). Use a water spray to clean them from the inside out. For vehicles with aftermarket headlights - pay special attention to wiring modifications as improper connections might keep the fan relay constantly powered. The easiest diagnostic method is using an OBD scanner to monitor real-time coolant temperature. If the fan runs wildly while temperature stays below 100°C, it's almost certainly an electrical control circuit problem.

[DelHarmony]

New car owners, don't panic. First, check these: After starting the car, wait three minutes to see if the fan speed stabilizes. If the speed fluctuates, the battery might be low. Inspect whether the 30A fuse labeled SB12 in the fuse box is blown. Additionally, test by pressing the AC switch; if the fan continues to run after turning off the AC, it indicates a fault. The electronic fan resistor module on the Tiguan, located at the back of the fan, is particularly prone to failure. It's available on Taobao for just over a hundred yuan, and those with good DIY skills can replace it themselves.