after removing and replacing the serpentine belt, does the engine light need to be turned off? and also, why does the electric fan come on and not turn off?

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! Replacing the serpentine belt shouldn’t trigger the engine light, but the shredded belt may have damaged nearby components or wiring—especially to the coolant temperature sensor. The electric fan staying on is a classic sign that the sensor isn’t sending proper data to the engine control unit (ECU), so the fan runs as a failsafe to prevent overheating. First, double-check the area where the belt shredded. Look for cut or disconnected wires, particularly near the coolant temp sensor or fan relay. After repairs, you can clear the engine light using an OBD-II scanner. If the issue isn’t fixed, the light will return. If everything checks out but the fan keeps running, it could be a stuck relay or a fault in the ECU itself. If you need any further advice or want help finding a trusted RepairPal shop in your area, please feel free to call us at 877-913-1554.