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Is your air conditioner outside unit fan not working? This can be really frustrating. There are few things that can prevent your ac outdoor unit fan from working. These include:
- Power issues
- Bad fan motor
- Dead start capacitors
- Defective contactor
- Issues with belt
Now let’s jump right into the details of each of the above issues.
Read also: AC Not Blowing Cold Air [7 Easy Solutions]
5 Reasons for Air Conditioner Outside Unit Fan Not Working
When you turn on your air conditioning system and the outside unit fan is not working, the following are some of the possible reasons for this problem.
1) Power Issues
Power disruption to your outdoor unit is a common reason for your outdoor unit fan not spinning. And usually when there is power cut to your outdoor condenser unit, the compressor will not work too. Your outdoor unit will just sit there, and nothing will happen.
So, if the ac fan is not working and the compressor is also not making any noise at all, this is a sign that your outside unit is not powered up.
How do I fix this issue?
When both the fan and the compressor are not working, it’s probably because of a tripped circuit breaker, electrical wiring issues or a power switch that is turned off.
Start by first checking with the condenser unit power supply if you are using a heat pump. A power switch for an outdoor unit can be found on the wall near the refrigerant lines that go into your home. Turn on the switch if it’s off.
However, if the power switch is on and your fan is not working, then go to the electrical panel to check the circuit breakers. The circuit breaker for your outside unit will be labelled ‘air conditioner. If you find it in the middle position, then its tripped and you should rest it.
If resetting the power switch and the breakers does not restore power to your ac outdoor unit then there could be problems with electrical wiring somewhere. It’s smart to call in a licensed HVAC technician to come and have a look.
This problem should be sorted out by an HVAC profession in no time.
2) Bad Fan Motor
A Bad fan motor can prevent your AC outdoor unit fan from working. If your compressor is working when you turn on your air conditioner, but your fan is not spinning, this could be a sign of a bad fan motor.
Sometimes fan motors can get blown out with time or when they are overworked and overheat. A fan motor that is going bad will usually produce strange noises. Your fan motor can go bad if there is rust building up in its internal components or when there is damage in its motor windings.
How do I fix this?
When you have a bad fan motor, you will need to replace it. You can call a local HVAC professional so that they can advise on what to do.
3)Dead Start Capacitor
A defective start capacitor will not start your AC fan. The start capacitor gives the fan motor the energy to start running. When you have a defective start capacitor, it will not be able to start your motor. Try turning on your ac and giving your fan a little push with something like a long screwdriver or a dry wooden stick.
If the fan starts running and spinning on its own after a little push, you might have a bad start capacitor. Otherwise, if the fan fails to take off, you may be dealing with a fan motor that is defective.
When you have a bad start capacitor, turn off your AC to protect your fan motor from possible damage.
Start capacitors are replaceable and if you are a DIY kind of a person, you can replace the capacitor yourself. Just check the type of capacitor that goes in your ac before getting a new one. You can do this by taking a photo of the sample and showing your seller.
Alternatively, you can just get the model number and search for it on online.
4) Bad AC Contactor
A defective or bad ac contactor will not power up your AC unit together with the fan. A contactor is an important part of your AC system that switches on and off the electric circuit. When you turn on your thermostat to start cooling, the ac contactor will turn on the circuit for the ac to start running.
However, sometimes a bug or something can get stuck in the ac contactor and that can stop it from working properly.
When the contactor is stuck in the upper position, it’ll cut the flow of electricity to the other components of the ac unit. Because of that, your ac won’t turn on and your fan will not spin even if you adjust your thermostat to cool.
But if the ac contactor is stuck in the down position, it will continue conducting electric flow to all other parts of your ac unit and the fan will continue running even when the thermostat is turned off.
When you have a bad ac contactor, you’ll need to replace it with a good working one. If you are a DIY person, you can order it online but make sure you take note of the model number.
5) Issues With The Belt
A belt that slipped out of pulleys or one that is broken won’t be able to drive your fan. This belt issue is common in order ac systems. If you have a newer AC system you probably won’t face this problem as new AC units don’t use belts to link the fan to the motor.
A belt that slipped from pulleys can easily be fitted back in place. But when belt issues occur, this could also be a good for you to start thinking about upgrading your system.
Also read: AC Thermostat Not Working [Solved]
What causes start capacitors to fail?
In most cases, it is overheating that will cause the AC start capacitor to fail. Unlike the ‘run’ capacitor that gives continuous power to the motor for running, a start capacitor is designed to stay in circuit for a short time. That is, when your motor is starting. A failed start capacitor is a common reason for your AC fan not working.
What causes a condenser fan motor to overheat?
Lack of regular and proper lubrication of a fan motor is a common reason why fan motors overheat. From time to time, ensure that your fan motor is properly lubricated for smooth running. Generally, it is best to have scheduled maintenance for your air conditioner at least once a year.
If your fan motor is old, it could also be overheating. And if your fan motor is overheating after you recently replaced it, check if you have the correct size of the fan motor, usually, a smaller size than needed will overwork and eventually overheat.
Should a fan motor get hot?
The simple answer is NO. If your fan motor is getting hot, then there is a problem with it. Under normal working conditions, a fan motor gets warm and that is how they are designed to work. It can work the whole time, but it should never get hot.
In this article, we have seen the possible causes for your air conditioner outside unit fan not working. But we recommend you have scheduled regular ac maintenance to avoid this problem and many other unforeseen AC break downs. Thanks for reading.
HVAC tech with over 30 years of experience. Retired and doing repair work on the side around Madison County, AL.