What is the reason why the car's AC fan does not turn on?
4 Answers
The reasons why the car's AC fan does not turn on are as follows: 1. Relay failure: If the relay fails, the car's radiator fan will not work. If the water temperature is normal but the radiator fan still does not work, the issue may lie with the fan's relay. 2. Poor contact: Poor contact in the main control switch or damage to the fan motor coil. Use a multimeter to measure the contact resistance of the main control switch. If the resistance is too high or zero, repair or replace the switch. 3. Loose screws: The fastening screws between the fan motor and the fan blade may be loose. Tighten the fastening screws. 4. Open or short circuit: The fan capacitor may be open or short-circuited. Check the capacitor and replace it with one of the same specifications.
Last time I drove with the AC on, I noticed the fan wasn't working, which made me sweat in panic. I pulled over to check it myself. Possible causes include a blown fuse—it's easy to replace the corresponding AC fuse in the engine compartment fuse box; or a faulty relay, just unplug and replace that small box; or the fan motor might be stuck or broken—try gently turning the blades to see if they move smoothly. Wiring issues are also common, like loose connectors or aged/damaged wires. If left unfixed, the AC will blow hot air, and the engine compartment temperature will skyrocket, damaging car components. Safety first—get it fixed ASAP. If you can't handle it yourself, take it to a repair shop without delay.
As a car enthusiast, I've found that when the fan doesn't spin, you should investigate the power supply system: blown fuses are highly probable due to short circuits or overloads; relay failures are common in damp conditions or from aging—measure contact continuity; fan motor issues like seized bearings or worn carbon brushes can be identified by unusual noises and vibrations; and there's also control module malfunctions, such as temperature sensor false readings. Using a multimeter to measure voltage is highly accurate, and replacing parts only costs a few dozen bucks. In terms of impact, a non-spinning fan leads to poor condenser heat dissipation, significantly increasing compressor load and reducing AC efficiency.
After years of family car use, I'm most concerned about safety when the fan stops working. A halted fan worsens AC cooling, allowing heat to accumulate in the engine compartment, making long trips prone to breakdowns or triggering high-temperature warnings. Check these basics: see if the fuse is blown, try replacing the relay, and check for dust buildup blocking the fan blades. If simple fixes don't work, head to a professional repair shop immediately to avoid roadside emergencies. Summer is especially dangerous - my personal experience reminds me that timely action is crucial. Never compromise safety to save money.
