3 Reasons Why Air Conditioner Fan Not Spinning? (How To Fix)

Last Updated on April 7, 2023 by Kimberly Crawford

Air conditioners provide relief from hot summer days and provide a comfortable indoor environment. Maintaining an air conditioner is essential for its efficient functioning, as even small issues can lead to serious problems.

One such issue is the fan not spinning in the air conditioner unit. This problem can cause the air conditioning system to struggle with cooling or heating the environment, making it difficult to maintain indoor temperatures.

It is, therefore, important to identify and solve this issue quickly. In this comprehensive guide, we will discuss the prevalence of air conditioner fan not spinning problems and provide helpful tips on how to fix them.

In this article

Common Causes: Understanding the Reason Behind Air Conditioner Fans Not Spinning

air conditioner fan

1. Motor Issues

Burned Out

The air conditioner fan motor can burn out over time due to wear and tear or from electrical overloads caused by faulty wiring, a failing capacitor, or an overheating issue.


Air conditioners are designed to run at a certain temperature range; when the system is overworked, it can cause the motor to heat up beyond its limits. This will put a strain on the motor and eventually cause it to fail.

Electrical Faults

Poorly installed electrical wiring or faulty power outlets can create an overload on the air conditioner fan motor which will lead to failure.

2. Capacitor Problems

Malfunctioning Start Capacitor

The start capacitor helps to initiate the movement of the fan motor and when it fails, the fan will stop spinning. If the capacitor is not replaced quickly, it may cause further damage to the entire system.

Capacitor Lifespan

Capacitors are not designed to last forever and will eventually need to be replaced. As the capacitor ages, it can become worn down which can lead to an electrical overload on the system or a malfunctioning start capacitor.

3. Debris and Obstructions

Accumulation of Dirt and Dust

Dust and dirt can accumulate on the fan blades over time, causing them to become clogged. This prevents the fan from spinning properly and can cause overheating as well as a decrease in air flow.

Foreign Objects Stuck in The Fan

If foreign objects such as leaves or twigs are stuck in the fan, it will prevent it from spinning and can cause damage to the motor if not removed quickly.

3. Electrical Issues

Faulty Wiring

Poorly installed electrical wiring or faulty power outlets can create an overload on the air conditioner fan motor which will lead to failure.

Blown Fuses or Tripped Breakers

If a fuse or breaker trips, the air conditioner fan will not be able to run properly and may require replacement. In some cases, resetting the fuse or breaker may resolve the issue. However, if this does not work, it is best to contact a professional for assistance.

Troubleshooting: Steps to Identify and Fix the Air Conditioner Fan Not Spinning Issue.

1. Preliminary Safety Measures

Turning off power to the unit

Before attempting any maintenance or repairs, it is important to turn off the power to the air conditioning unit by flipping the switch located on the circuit breaker. This will help ensure your safety and prevent any electrical shocks while working on the system.

Gathering necessary tools and equipment

Make sure you have the proper tools and materials to complete the job. This can include a screwdriver, wire cutters, voltage tester, capacitor testing meter, and replacement parts such as capacitors and fuses if needed.

2. Inspecting the Fan and Surrounding Area

Identifying visible obstructions

Inspect the fan and surrounding area for any dirt, dust, leaves, twigs or other foreign objects that may be preventing the fan from spinning properly. If necessary, use a vacuum cleaner to remove any debris.

Cleaning the fan blades and housing

Once all obstructions have been removed, carefully clean the fan blades and housing to remove any built up dirt or dust. This will help improve air flow and prevent overheating.

3. Testing the Motor

Assessing motor performance

To check if the motor is functioning properly, turn on the power to the unit and listen for any strange noises that could indicate a malfunctioning motor. If everything sounds normal, you can then check the voltage to ensure that the correct amount of power is being supplied to the motor.

Checking for signs of overheating

Overheating can cause a variety of issues with air conditioning units, so it is important to inspect the motor for any visible signs such as scorch marks or melted wires. If necessary, use a heat gun to check for excessive temperatures.

4. Capacitor Examination

Identifying a swollen or leaking capacitor

The capacitor is an important component of the motor and can cause issues when it begins to fail. To check for any problems, inspect the capacitor for signs of swelling or leaks. If either of these is present, it will need to be replaced as soon as possible.

Testing the capacitance

To test the capacitance of the capacitor, use a capacitor testing meter to measure its resistance and see if it is within normal parameters. If not, it should be replaced as soon as possible to prevent further damage to the motor.

5. Electrical Issues

Inspecting wiring connections

Once you have tested the motor and capacitor, it is important to double check all of the wiring connections to make sure that they are secure and free of any corrosion or debris. If any of these are not in proper working order, they should be replaced or reinstalled.

Replacing blown fuses or resetting breakers

If the voltage has been tested and all of the wiring is secure, it’s time to check for any blown fuses or tripped circuit breakers that may be causing the problem. Replace any defective parts as needed and reset any circuit breakers that have been tripped.

Causes of the Issue: Air Conditioner Fan Not Spinning But Hums

air conditioner fan not spinning but hams

1. Faulty Capacitor

The capacitor is an electrical component which stores energy and helps to start the motor of the air conditioner fan. It also assists in running the fan at its best speed for optimum airflow output.

If the capacitor develops a fault, it will not be able to store enough energy to start the fan motor. This will result in the fan not spinning, but producing a humming noise as it attempts to run.

2. Broken Fan Motor

The fan motor is responsible for powering the fan blades and providing them with enough power to rotate at the required speed for airflow production.

If the fan motor becomes damaged, it will not be able to provide enough power needed to turn the fan blades. This can lead to the fan producing a humming noise but not spinning.

3. Damaged Fan Blades

The air conditioner fan blades are responsible for generating airflow when they rotate at the correct speed. If any of these blades become bent or broken, they will not be able to turn as smoothly or at the speed needed for efficient airflow output.

Some types of fan blade damage include impact damage and corrosion, which can cause the blades to become misaligned, bent or even break off. This will cause the fan to produce a humming noise without spinning.

4. Loose Electrical Connections

The electrical connections to the fan motor need to be firmly connected and secure in order for the motor to receive enough power and therefore operate correctly.

If these connections become loose or are not properly attached, it can lead to the fan humming without spinning due to lack of sufficient electrical power being received by the motor. This can also cause sparks and other electrical hazards.

Troubleshooting Tips: How to Fix an Air Conditioner Fan Not Spinning But Hums

1. Checking the power supply and breaker

To check for proper power supply to the air conditioner, make sure that the main switch is turned on and inspect all wiring connections from the unit to the wall receptacle. If there is no power reaching the unit, try resetting any tripped breakers or replacing blown fuses.

If the breaker or fuse is tripped, determine why by inspecting the wires and circuit components for signs of damage or miswiring. If no issue is found, reset the breaker or replace the fuse and see if the fan starts spinning again.

2. Inspecting the fan blades

Inspect all visible parts of the fan blades for signs of damage such as cracks or other physical defects. If any damage is found, replace or repair the affected parts as necessary.

Make sure that there are no obstructions blocking the fan blades from spinning freely and check for proper alignment of all components within the unit.

3. Testing the capacitor

Use a multimeter to test the capacitor for any faults that may be preventing the fan from spinning. If there is a fault detected, replace the capacitor with a new one as soon as possible.

Once the new capacitor has been installed, check to make sure that it is functioning properly and that the fan starts spinning again.

4. Examining the fan motor

If the capacitor and fan blades have been inspected and there is still no spin, it is likely that the fan motor has become damaged in some way. To identify any potential problems with the motor, inspect all wires and connections for signs of damage or corrosion.

If any damage is found, repair or replace the fan motor as necessary.

5. Tightening loose electrical connections

The fan may not be spinning because of loose wires and connections within the air conditioning unit. To fix this issue, locate any loose connection points and use pliers to securely tighten them in place.

After ensuring proper functioning of all connections, test the fan again to make sure that it is spinning correctly. If the fan does not start up, you may need to investigate further and contact a professional HVAC technician.

Reasons for AC Fans Not Spinning After Replacing Capacitor

1. Faulty or Incompatible Capacitor

Incorrect Voltage Rating

The AC fan may not spin when the replacement capacitor has a voltage rating that is different from the one it replaced. This is because the wrong voltage rating can create an imbalance in the system, resulting in insufficient power to start the motor and cause it to spin.

Incorrect Capacitance Value

The replacement capacitor should have the same capacitance value as the one it replaced, otherwise the incorrect capacitance value may not provide enough power for the motor and cause it to fail to spin.

Defective New Capacitor

If the new capacitor is defective or of poor quality, then it may not provide the necessary power to start and run the fan motor.

2. Incorrect Wiring During Capacitor Replacement

Mistakes in Reconnecting Wires

If mistakes are made in reconnecting wires while replacing the capacitor, then this can lead to incorrect wiring which may prevent the motor from starting.

    a. Wrong Terminals: This can happen when the wires are connected to the wrong terminals, which may cause inadequate power flow and Prevent the fan motor from spinning.

    b. Loose Connections: Loose connections in the wiring can also prevent sufficient power flow, resulting in the AC fan not spinning.

3. Damaged Fan Motor

Worn-out Motor Bearings

The fan motor bearings may wear out or become degraded over time, reducing the effectiveness of the motor and preventing it from spinning when power is applied.

Damaged Motor Windings

If the motor windings have been damaged, then this can also prevent the motor from spinning when power is applied.

4. Malfunctioning Control Systems and Switches

Faulty Thermostat

A faulty thermostat may cause the AC fan not to spin due to insufficient power flow, or by interrupting the circuit and preventing the fan from starting.

Tripped Circuit Breaker or Blown Fuse

A tripped circuit breaker or blown fuse can also be responsible for the AC fan not spinning, as they may cause an interruption in power to the motor.

Damaged Fan Relay

If the fan relay is damaged, then this can prevent the motor from receiving power and prevent it from spinning.

Solutions for AC Fans Not Spinning After Replacing Capacitor

1. Properly diagnose the problem

Check for power supply to the fan and ensure that it is present and functioning properly.

Take readings from capacitor leads using a multimeter, making sure that the capacitance reading matches with the value specified on the capacitor label.

Inspect other components of the fan such as the motor and blades for any signs of damage or wear.

See if there is a humming sound coming from the fan, which could indicate that power is reaching the motor but it isn’t spinning due to a faulty capacitor or broken wiring.

2. Replacing faulty or incompatible capacitors

Make sure to purchase a new capacitor with the same voltage rating and capacitance value as the original one.

Carefully read the instructions provided by the manufacturer before proceeding with installation of the new capacitor.

Using insulated tools, disconnect the wiring from old capacitor and connect it with new one, ensuring that all connections are secure and tight.

Test the new capacitor with a multimeter before installing it into its place.

3. Correcting wiring mistakes

Disconnect power supply to the fan before proceeding with any repairs or adjustments to wires or terminals.

Carefully inspect all connections, making sure that they are tight and secure.

Make sure that the correct polarity is being followed when connecting wires, to avoid accidents or potential damages.

4. Repairing or replacing damaged fan motor

Inspect the motor for any signs of wear or damage such as a burnt smell or visible corrosion on its surface.

Clean the motor thoroughly with a soft cloth and lubricate its bearings if necessary.

If the motor has sustained too much damage, it may need to be rewound or replaced with a new one.

5. Addressing malfunctioning control systems and switches

Check the thermostat if it is functioning properly and check for any faulty wiring.

If the fan does not start after turning on the switch, then reset the breaker or replace fuses to restore power supply.

Test the fan relay and make sure that it is in working condition by replacing it with a new one if needed.

Make sure to disconnect power supply from fan before making any repairs or adjustments to its control systems or switches.

Once all these steps are taken, the AC fan should be able to spin again and cool down your home.



Properly addressing air conditioner fan not spinning issues should be a priority for all homeowners. Quick and effective troubleshooting can help to identify the source of the problem, but professionals may need to be consulted for more difficult repairs. Additionally, regular maintenance and cleaning can help to prevent future problems from arising. With these measures in place, homeowners should be able to enjoy the cooler days of summer with a well-functioning air conditioner.