The fan clutch is one of the most important components for cooling fan operation and a key factor in the engine’s overall performance.
Having your air conditioning system suddenly stop blowing cold air could disrupt a smooth ride, especially during the summer. When driving on the highway, everything may seem fine, but when in stop-and-go traffic, you will notice that it has stopped blowing cold air.
Could it be that there is an issue with the fan clutch? The answer is yes.
Therefore, if you are constantly experiencing problems with your AC, make sure to read till the end for a long-lasting solution. Because in this article, we’ll explore the relationship between the fan clutch and the AC system, and see if a faulty fan clutch can lead to AC issues.
Table of contents
- What is a Fan Clutch?
- How Does a Fan Clutch Work?
- Types of Fan Clutches
- How Does a Bad Fan Clutch Cause AC Problems?
- Other Symptoms of a Bad Fan Clutch
- How to Diagnose a Faulty AC Fan Clutch
What is a Fan Clutch?
This is a device responsible for regulating the temperature of a car’s engine. Your car engine generates an amount of heat that would require the functionality of a cooling fan, and a fan clutch is useful to keep the fan active.
Not all vehicles have the same clutch. Much newer vehicles have an electronic fan powered by the car’s computer, while much older vehicles have the mechanical fan clutch mounted directly to the water pump to help control the fans.
How Does a Fan Clutch Work?
If this is the question running through your mind, you need to understand that there are different types of fan clutches.
Although their primary function is to keep your car’s engine and cooling system cool, some fan clutches engage at around 170°F air temperature and reduce to an average temperature of around 20°F before disengaging.
Some fan clutches engage at around 170°F air temperature and reduce to an average temperature of around 20°F before disengaging. And they also stop spinning when the car drives at a speed that pushes air through the radiator.
While some clutches require more power to operate and engage continuously, regardless of temperature, others do not.
Types of Fan Clutches
1. Thermal Clutch
This clutch fan operates using silicon fluid, and it has a small spring located up front. This spring expands whenever the air between the radiator and the fan gets hot—approximately 170 degrees Fahrenheit—and it opens up a valve, which lets the silicone move freely inside the fan clutch.
When this happens, the centrifugal force from the engine spinning will cause the water pump to shoot out some fluid while spinning. This then activates the fan clutch, making the fan turn at an increased RPM and drawing enough air to cool your car’s engine and its cooling system.
Also, note that once your fan clutch maintains a 170-degree Fahrenheit, it actuates. When it does, it tries to maintain a specific operating temperature for your vehicle, which could be approximately 195 to 220 degrees.
After cooling, the spring contracts, stopping the flow of silicone and storing it in the reservoir. This process lowers the friction on your fan clutch and would cause it to spin at a lower percentage.
2. Non-Thermal Clutch
This clutch looks like a thermal clutch, but it does not have a spring in front. Also, it does not need to know the temperature of the surrounding air. It spins at a speed of approximately 30%- 60% of the pulley where it is mounted.
A non-thermal clutch delivers a constant flow of cooling air because it is continuously on. However, it does not save as much fuel as a thermal clutch.
3. Electronic Fan Clutch
This model functions just like the thermal clutch. However, the Power Control Module (PCM) or Engine Control Module (ECM) signal regulates the degree to which the electric vehicle clutch engages.
As a result, it is not directly controlled by temperature; rather, it depends on a number of sensors to determine when to activate or not.
How Does a Bad Fan Clutch Cause AC Problems?
A fan clutch is one of the components in a vehicle that most people don’t consider until it breaks down, and this could be a big deal when it happens.
It regulates the amount of power applied to the cooling fan in your vehicle and helps to maintain a consistent engine temperature.
So, when the clutch is bad, it starts to spin freely. This will fail to enable the AC compressor to pull enough air through the cooling fins of the condenser. As a result, your AC will start running at very high head pressure, causing it to stop blowing cold air.
Other Symptoms of a Bad Fan Clutch
1. Engine Overheating
Overheating is one of the typical signs that a fan clutch is bad. When your fan clutch can not engage properly, the cooling fan’s performance declines, causing your engine to overheat.
However, when you fail to address this condition quickly, it could result in far more serious problems, which we are sure you wouldn’t want to experience.
Therefore, it is safer to consult a professional who can identify the true cause. Rather than adding water to the radiator when you discover your vehicle is overheating.
2. Improper Condenser Airflow
Defective fans can cause numerous problems which can affect the functionality of the ac in your vehicle.
When your ac clutch fan is bad, there will be a lack of airflow through the condenser, causing the high and low side pressure to go up from 350 to 450. And this would stop it from blowing cold air, especially while you are stuck in traffic.
3. Poor Performance
Another common signal that something is wrong is the lack of power, a drop in acceleration, and a reduction in fuel efficiency.
When there is a problem with the clutch, it results in a permanently engaged fan, which causes an excessive drag on the engine.
4. Loose Fan
The engine fan could become loose and unstable due to a failing fan clutch. The fan wobbles at high speeds, especially while driving on the road.
This can be embarrassing most times…
Therefore, to find out if your fan is loose, you can simply park your car and turn on the engine with your hood open. Then, look to see if the fan is swaying while it spins. You can also check if oil is dripping from the clutch hub.
How to Diagnose a Faulty AC Fan Clutch
1. Spin the Fan
If the fan spins more than three times, or if it doesn’t spin at all—which means the bearing might be seizing—then you probably have a bad fan clutch.
However, clutches like the electronic fan clutches might freewheel and spin with a little effort.
2. Wiggle the Fan
Attempt to move the fan forward and backward if you hear it click or see it wobbling more than a quarter-inch. It may be a sign of a broken bearing.
3. Check for Leaks
The thick silicone fluid that the fan clutch uses is essential for how it works. Therefore, if any leaks occur, the clutch would deteriorate and eventually fail.
How Can I Repair/Replace a Bad AC Fan Clutch?
The following are the steps you can take to replace your damaged clutch:
- Locate the fan clutch–Usually located at the front of the engine, between the radiator and the engine.
- Remove the fan blade–Loosen the bolt or bolts that hold the fan blade in place to do this.
- Remove the fan clutch–Use a fan clutch removal tool, which can be purchased at an auto parts store.
- Install the new fan clutch–Align the splines on the new fan clutch with the splines on the water pump and then tighten the bolt or bolts to secure it in place.
- Reinstall the fan blade–Tighten the bolt or bolts to secure it in place.
A faulty fan clutch can cause AC problems in your vehicle. It stops the air conditioning system from pulling enough air through the condenser to stop the AC pressure from rising. This can result in a lack of cooling or a complete failure of the air conditioning system.
Therefore, it is important to replace your fan clutch as soon as you can if it’s broken to avoid having issues with your AC or even damaging your engine.