What Are the Reasons for the Car Air Conditioner Fan Not Turning On When Activated?
4 Answers
There are several reasons why the car air conditioner fan does not turn on when activated, including poor contact of the main control switch, damage to the fan motor coil, and detachment of the fan bearing. Poor contact of the main control switch: If the air conditioner switch has poor contact, it cannot control the normal activation of the car air conditioner, and the lack of connection between the two leads to the fan not turning on. Solution: Replace the air conditioner control switch and check for any short circuits in the connecting wires. Damage to the fan motor coil: If the fan motor coil is damaged, the fan cannot receive power normally, resulting in it not turning on. Solution: 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 component. Detachment of the fan bearing: When the fan bearing is detached, activating the air conditioner causes the bearing to spin idly without the fan turning normally. Solution: Reinstall and secure the fan bearing. How the car air conditioner works: The car air conditioning refrigeration system consists of a compressor, condenser, liquid storage dryer, expansion valve, evaporator, and blower, among other components. These parts are connected by copper pipes and high-pressure rubber hoses to form a sealed system. When the refrigeration system operates, the refrigerant circulates in different states within this sealed system.
I've driven for many years and encountered various reasons for the AC fan not working. The most common issue is a problem with the fan motor, which can be due to aging causing it to seize or bearings getting stuck. A blown fuse is another frequent cause, as it breaks the circuit when the current is too high. Loose or corroded wiring connections can prevent proper current transmission, especially near the headlight switch where connections tend to loosen. A faulty relay can also stop the fan from working, as this component controls the fan's activation. Additionally, if the control module is damaged, it affects the entire system, preventing the fan from turning. In such cases, it's best to first check the fuse box and use a multimeter to test if the voltage is normal. If not repaired promptly, the excessive heat inside the car during summer can affect driving safety, so it's advisable to have a mechanic inspect it.
I enjoy working on my own car. If the fan doesn't spin when the AC is turned on, my first instinct is to check the fuse. Usually, I look for a blown fuse marked with a fan symbol in the engine compartment's fuse box—if it's blown, I replace it with a new one to test. If the fuse is fine, the issue might be poor wiring contact, like a loose or corroded plug interrupting the current. Fan motor failure is also common, as prolonged operation can cause wear or jamming. If the relay is faulty, the fan won't start—listen for a clicking sound from the relay. Control circuit issues, such as a short or open circuit, can also prevent the fan from spinning. I recommend checking on a clear day to see if the fan blades are blocked by debris, then testing the voltage. For safety, disconnect the battery before working. If you can't figure it out, take it to a repair shop.
There are several key reasons why the air conditioning fan may not be working: first, the fan motor may have failed or burned out; second, a blown fuse may have interrupted the circuit; third, wiring issues such as poor contact or open circuits could be the cause. Fan motor problems are quite common due to prolonged operation leading to wear and tear. Loose wiring connections near the air conditioning components can also cause this issue. Relay failures can prevent the fan from starting, and a damaged switch is another obvious culprit. Control module issues, including sensor errors, can also halt the fan. When troubleshooting, first check if the fuse is intact, then inspect whether the connections are secure. Timely maintenance is crucial to avoid insufficient cooling, which can affect in-car comfort.
