How do you know if your AC fan motor is bad?

Be aware of the following signs and symptoms of a bad AC fan motor.

  1. AC Fan Doesn’t Start. Even though you have the AC turned on, the fan does not start.
  2. AC Fan Doesn’t Stop. …
  3. Slow Rotating Blades. …
  4. Outside Fan Blades Are Still. …
  5. Rattling, Humming, and Buzzing Noises. …
  6. AC Runs Intermittently. …
  7. No Cold Airflow.


How do I know if my condenser fan capacitor is bad?

The fan won’t start even though the AC is on. The fan won’t stop, even when you shut the AC off. The fan turns on, yet the blades are rotating very slowly. There’s a rattling noise coming from the condenser unit when the fan is turned on.

What causes a fan motor to stop running?

One of the most common reasons fans stop spinning is because of a dead capacitor. The AC’s capacitors are small, cylinder components that send energy signals to power the fan motor and the rest of the AC unit.

How do you test a fan motor?

Quote from the video:
Quote from Youtube video: Will be on the fan. And your black wire will be coming off the defrost. Board off the df2 there so you want to pull the wires then we omit. Out pull the black off the df2.

How do you test an air conditioner fan?

Quote from the video:
Quote from Youtube video: And the lower number will be for the fan motor. You can verify. The you F or M FD micro farad reading they're both the same they both mean the same thing.

What causes outside AC fan to stop working?

If the fan doesn’t start running, you may have a bad fan motor. If you have difficulty getting the blades to turn, there may be debris wrapped around the fan axle, or the motor bearings may be dirty or jammed.

Will AC fan run if capacitor is bad?

The simple answer is “No.” There are two types of capacitors–the start capacitor that signals the AC motors to start up, and the run capacitor that keeps those motors running through each cooling cycle.

How do you diagnose a bad AC capacitor?

Bad AC Capacitor Symptoms Checklist

  1. Smoke or a burning smell from exterior air conditioning components.
  2. A humming noise from your air conditioner.
  3. Your air conditioner takes some time to start a cooling cycle once you turn it on.
  4. The air conditioning system shuts off at random.

How do I test an AC compressor capacitor?

Quote from the video:
Quote from Youtube video: Use a probe to touch one of the terminals. And the second probe to touch the other terminal. The meter needle should deflect toward zero ohms.

How do I test a fan capacitor?

Disconnect the wires that run from the capacitor to the motor. Switch the volt meter to the ohm setting. Place the leads of the ohm meter on the wires that run from the capacitor to the motor. Count to three while the leads on the meter charge the capacitor.

How do you test a fan motor with a multimeter?

To test your motor for short to ground, you’ll need to set the multimeter to ohms and disconnect the motor from its power source. Then inspect each wire and look for infinite readings. Alternatively, if you get a reading of 0, you might have a cable issue.

What causes AC fan motor to burn up?

Like any motor, an air conditioner fan motor can become overheated if it works too hard and doesn’t receive proper maintenance. If your AC has worked for you most of the summer, the stress could cause the fan motors to burn out.

How much is a AC fan capacitor?

AC Capacitor Cost



The cost of an AC capacitor is typically between $9 and $25. Professional installation usually costs between $60 and $200. Replacing this part is a common AC repair cost and is often relatively inexpensive. However, depending on the type of capacitor you need, prices will fluctuate.

What happens if condenser fan doesn’t work?

If the condenser fan is running you will see the fan blade spinning at speed (typically at 1725 rpm) and you will feel air blowing out of the unit. at BURNED-OUT COMPRESSOR, if the condensing unit fan is not working the compressor itself may shut down or even be ruined by overpressure or over temperature.

Why is my central AC running but not blowing air?

If the AC unit is running, but there is no air through the vents, you are likely dealing with a fan capacitor that has reached the end of its life. Fan capacitors help get your HVAC system’s outdoor and indoor fan motors blowing and your compressor running.

Can Hear AC running but no air?

The common complaint is, “I can hear the air conditioner turn on but no air is coming out.” That’s because coil inside the AC unit is frozen. One reason for AC freeze-up is that the air flow coming into or out of your system is blocked at some point.

How do I fix my central air conditioner that is not cooling?

If your air conditioner will turn on, and your thermostat is set properly, but your system is not cooling you may have a dirty or blocked air condenser. Your first step is to check the outside unit and clean around and remove any debris or weeds that are blocking air circulation.

How do I reset my AC compressor?

How to Reset an Air Conditioner

  1. Power down your AC. Start at your circuit breaker panel and flip the breaker that powers your AC. …
  2. Find the button. Most air conditioning units are equipped with a reset button. …
  3. Hold down the reset button for 3 to 5 seconds and then release.
  4. Restore power to your AC.