Carrier Air Conditioner Fan [Issues & Solutions]

A Carrier air conditioner fan is part of the cooling system and usually runs while the compressor runs. If it becomes faulty, the unit cannot function the way it should. Fortunately, there are solutions to possible issues.

Carrier air conditioner fan

Carrier Air Conditioner Fan Not Working – How to Fix

Several things cause an air conditioner fan not to work. The following are parts to check and fix or replace if the fan in a Carrier air conditioner is not working:

1. Dual Shaft Fan Motor

Some air conditioner models use a dual shaft motor where the motor has a blade on either side of it. The blades have different functions; one blows air over the evaporator coil while the other blows air over the condenser coil.

The motor of this dual shaft fan can get faulty over time, especially if it is in use for a long time. The bearings may bind or loosen, causing the motor to stop functioning. And if the motor does not run, the fan cannot run. Turn the shaft to see if it is loose or stiff. If it does not turn at all or turns too freely, the motor needs a replacement.

2. Thermostat

Turn on the air conditioner and set the operating mode to Cool. Next, get a multimeter and run a continuity test on the thermostat. While the air conditioner is in the cooling mode, the thermostat should show continuity. But if there is no continuity, it is time to replace the thermostat.

The thermostat keeps an eye on the air temperature to know when it drops or rises. If the temperature increases beyond a preset point, the thermostat activates the selector switch to send power to the fan and compressor. However, the thermostat can become defective over time and keep the fan from working.

Note: Check the number of terminals on the thermostat before testing it. Typically, it should have two terminals but when it controls a heating element in the air conditioner, it may have more than two. Therefore, follow the instructions in the wiring diagram to continue the process if it applies.

3. Relay Board

The board sends voltage to several components of the air conditioner. One of those components is the motor of the fan. Without the board, the intricate process of supplying power to the unit’s moving parts becomes truncated. 

However, ensure you correctly diagnose the board before removing and replacing it. All boards are easy to misdiagnose and many good ones have been discarded. Other more commonly faulty parts should be tested before checking the relay board.

4. Temperature Control Thermostat

This thermostat is the one that controls the temperature settings within the home. It must have functional batteries and correct electrical connections. If its electrical contacts burn out, the thermostat stops functioning and may affect the fan. Take a multimeter and test the thermostat for continuity. Replace the thermostat if you find no continuity.

The fan should run at the same time as the compressor does, and the thermostat controls both components. So, if both of them do not run, the thermostat is the source of the problem. But if the fan does not run while the compressor runs, check the fan motor or capacitor.

5. Run Capacitor

Most Carrier air conditioners have a capacitor that powers both the fan and the compressor. The capacitor stores electric power to provide a boost for the fan motor and compressor to run. It is usually connected to the compressor by electrical leads in such a case. But in others, you may find that the fan has a separate capacitor. If the compressor and fan are not running, it is possible that the capacitor has failed. 

Sometimes, the compressor may still run while the fan stops working if the capacitor is bad. In the case where there is a separate capacitor, the capacitor is defective. Run a continuity test on the capacitor using a multimeter. Replace the capacitor if it does not register any continuity.

6. Fan Motor

Not all air conditioner fans are dual shaft fans. If your air conditioner has a separate fan for the condenser and indoor unit, check the fan motor to determine whether or not it is defective. Turn the blades of the fan outside the house; if they are stiff, it may indicate that the bearings are worn. If the motor bearings are worn, it is time to replace the motor.

However, if the blades turn well, the motor may not be receiving electric power. Test the fan motor using a multimeter and if it is getting power without running, replace the motor. Without the motor, the fan will remain stuck and stop working.

7. Thermistor

Locate the thermistor on the air conditioner’s control board and test it using a multimeter. Its resistance value must be the same as that on the specification sheet for the unit. But if the value is off, replace the thermistor.

It is a sensor on the air conditioner’s control board that senses the air temperature. If there is a need for cooling or warming, the sensor alerts the thermostat which, in turn, activates the selector switch to provide voltage for the cooling system. Therefore, the sensor must be in good working condition for the unit to run well.

8. Selector Switch

This switch ensures voltage reaches the compressor and fan. Go to the control board of the air conditioner and make selections. Check how the fan runs when you make these selections; if it only runs intermittently, it means the switch is faulty and needs a replacement. The same applies if the switch has smoke or signs of arcing.

9. Main Control Board

The control board governs the functions of the entire air conditioning system. If it malfunctions, one of the ways it shows is the fan; it may stop working. But before deciding on the main control board, it is recommended to check other parts of the system that are more likely to cause the problem. Troubleshoot the board and replace it if it is damaged and no other part is faulty.

Check out these other articles…

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Carrier Air Conditioner Blinking/Flashing [Proven Solution]

Carrier Air Conditioner Noise [Problems & Solutions]

Carrier Air Conditioner Control Panel [Problems & Solutions]

Carrier Air Conditioner Compressor [Problems Solved]

Carrier Air Conditioner Modes [Detailed Guide]

Carrier Air Conditioner Fan Not Spinning – Solved

There are a few reasons your Carrier air conditioner fan is not spinning. First, check the motor. It must be in good working condition. If the motor is not running, it may be time to replace it. Test it for continuity before replacing it. 

Second, check the fan blades; debris may be stuck in them or they may have fallen off the shaft. If there is debris, turn the air conditioner off and clean the fan. Ensure the blades sit securely on the shaft; you may have to tighten them. Also, ensure there is no bent blade; it may impede the fan’s functionality.

Third, the air filter may be extremely dirty, clogging the entire system and causing it to function improperly. If you have never replaced the filter or it has been in use longer than three months, it is best to remove the old filter, clean the air conditioner, and replace the filter. The air conditioner fan may start running again.

The thermostat setting may be wrong; if you set it in Heat mode of operation when your aim is Cool, the fan is likely not to spin. So, check the thermostat and adjust the setting for the mode and temperature. If the problem stems from there, the fan should begin spinning after the adjustment.

Note: These steps apply to both the blower and condenser fan. If the air conditioner is humming but the fan is not spinning, it means the unit is getting electric power and the compressor is in good working condition. The only reason the fan is not spinning if it is clean and the blades are intact is a defective motor. Consider replacing it; contact the Carrier Service Center or hire an independent technician.

Carrier Air Conditioner Fan Noise – Quick Fix

Fan noise from a Carrier air conditioner may be due to debris, loose blades, worn-out motor bearings, or a defective motor. You may hear a grinding, squealing, buzzing, clanging, or any loud noise from the unit because of the fan.

Check the motor; if the bearings are worn, replace the motor. The bearings cannot be repaired, so the only fix is to change the motor. Next, ensure the blades are secure on the motor shaft. Tighten them on the shaft if they are loose. Loose blades hit the sides of the housing and generate noise. The same is true if there is debris stuck in them or in the motor. So, thoroughly clean the fan while checking the blades.

If the motor is generating noise, it is usually an indication that it is wearing out. It may also mean there is internal damage. Several things can damage the fan motor, but it is best to replace the motor to stop the noise. Typically, the motor can remain functional for a while even with the noise. Unless the noise is beyond your tolerance, you may want to wait before replacing the motor.


The fan in an air conditioner is one of the most important parts. With it, the compressor and other parts of the cooling system can function to produce cool air. The same applies to a Carrier air conditioner fan. If the fan becomes faulty, there will be other functional issues with the air conditioner.

Check the run capacitor, thermostat, temperature control thermostat, air filter, fan motor, blades, and thermistor. Also, check the selector switch, relay board, and main control board for possible causes of a failed air conditioner motor. Troubleshooting these parts is usually easy, but some may require the services of a professional. The capacitor, for example, stores electric power that needs to be discharged before testing it.

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