AC Not Working - Outside Fan Running, Inside Fan Not

woman with fan looking at AC in wall

DIYers can solve many AC problems without calling in experts. Damaged fans, you can probably handle. Something more complex like a broken compressor will probably require professional attention.

There are two possible scenarios if you're experiencing problems with your AC fans. One is that your outdoor compressor is working, but the fan is not. The other scenario would be that you don't hear the outdoor compressor and the fan not spinning.

AC Compressor Working, Fan Not Spinning

When the compressor is working, its sound may be confused with the sound of a spinning fan. The observer may say the fan is spinning at a sowing rate. In reality, the sound is made by the compressor, The fan might appear to be turning slowly, but the movement is caused by wind blowing through it.

If the fan is not spinning but can hear a buzzing sound, you may have a motor problem. You may also be experiencing a terrible starter capacitor problem. The capacitor stores power and sends electrical jolts to start the motor.

If the capacitor is damaged, there will be no power to start the motor. We also have a run capacitor that gives the engine energy to keep running once it starts.

A regular AC system works with three different motors. We have the compressor, the indoor fan, and the outdoor fan motors. It's therefore vital for you to be able to ensure that all engines are running at all times.

If you have a bad starter capacitor, the fan will not start. To test whether the capacitor causes the problem, use a nonconducting material such as wood to jolt the fan so it starts moving manually. If it picks and continues spinning, chances are the start capacitor is the problem.

If the problem is the ruined capacitor, you can easily detect the fan's movements. If the run capacitor is spoiled, but the start is okay, the fan will start spinning but lose momentum and slows down. This scenario will repeat itself over and over.

If you try starting the fan manually and it does not pick up pace, you may have a bad motor. In some instances, it may just be the case of debris clogging the blades. You want to try and blow dust and debris off the fan before concluding that there is a motor problem.

man repairing an AC unit

Dealing With Bad Capacitor

If you realize that your capacitor is the problem, the solution is as simple as replacing it. However, this is a pretty technical job.

You have to remember that you will be working within a tight space. Further, it comes with a serious risk of electric shock, considering how much power AC systems use. Don't try it if you're not an experienced electrician.

Where Both Fan and Compressor are Not Working

The other potential fan problem may be that both the fan and compressor are not working. If you notice that your fans are running but the compressor is not, or both are not, you should know there is a power problem.

In most cases, this is caused by a disruption in the power supply, such that it does not get to the outer unit. The other possibility could be that you have a defective contactor.

Bottom Line

When you experience AC problems related to the fan or compressor, it is most likely a power supply issue or a bad capacitor problem. In some rare situations, the motor might have stopped functioning.

You may be able to deal with the problem at home in all of these instances. However, if you find the situation too complex for your skills, call an expert to help. Your safety is paramount.