Installation & repair

How to connect a 4-wire ceiling fan to a capacitor and how to replace ceiling fan switches

Installing a ceiling fan can be a daunting task, especially if this is your first time. Without the right instructions, it can be difficult to know how to connect a 4-wire ceiling fan to a capacitor. Because if you make a mistake while connecting the gearbox, without the proper knowledge and tools, installing a ceiling fan can be extremely dangerous leading to an accident or requiring more repairs. In this article at website and Toby Nwazor will give you step-by-step instructions, showing you how to connect 4 wire ceiling fan with capacitor. Plus, we provide tips on how to quickly and safely fix common problems of switches so you can enjoy a cool breeze from your new ceiling fan as soon as possible.

Overview of ceiling fan capacitors

You can check and test a capacitor by 6 methods if it is defective or in good condition. The following things will help you assemble and repair the ceiling fan capacitor simply without calling an electrician.

What is a capacitor?

Simply put, there is a single phase motor aka split phase induction in the ceiling fan where we need a starting capacitor to divide the phase angle between the starting coil and the running coil to generate a magnetic field. . The capacitor only does that because it provides a phase shift before the 90 degree rotation. In this way, the voltage across the starting and running windings with phase out of phase provides the rotating magnetic field which leads to the rotation of the motor’s rotor. Having knowledge about capacitors will help us know the best way to connect ceiling fan 4-wire to a capacitor.

You should remember that in each capacitor, even though it is different in shape, there is one common feature, there are two windings in the ceiling fan motor called the main winding when running and the auxiliary winding when starting. We need to connect the capacitor in series with the auxiliary starter winding.

What is the function of the capacitor in the fan?

The capacitor used in the fan has the effect of deflecting the magnetic field and providing a large voltage to start the fan, when the fan rotates normally, this capacitor is no longer effective. Therefore, if the fan capacitor fails or the capacity is not enough, the fan will not be able to operate. Thereby it can be seen that the capacitor used in the fan has the effect of deflecting the magnetic field.

How to connect 4-wire ceiling fan to a capacitor 

Meaning of each wire

Getting to know the wire colors of all 4 wire will be the most important step.

The color of the ceiling fan condenser wire may be slightly different from that of other household electrical wiring and should be investigated carefully. It is important to understand what each wire does and how it connects to the others.

  • The black wire is the hot wire leading to the switch.
  • The white wire is the neutral wire that completes the circuit.
  • The copper or green wire is the ground wire and keeps the fan from powering up.
  • If there is a blue and black wire coming from the circuit in the home, there must be two switches on the wall.
  • If there is a red wire from the ceiling, it is connected to the wall switch.

In addition, according to each type of ceiling fan, each wire will have different meanings. For example, with a ceiling fan light will have the following meaning:

  • Black wire for fan.
  • The blue wire is for the lights if one comes with the fan.
  • The white wire is the neutral wire.
  • The green wire is for ground.
  • The red wire is sometimes included and acts as a conductor to carry power to the luminaire.

Steps to connect 4 wires with capacitor 


Make sure that all circuit breakers are disconnected. Electrical boxes are usually located in garages or closets. If necessary, consult a professional electrician to ensure that the circuit breaker box and switch are in the correct code.

Also, you need to make sure to strip the coating on the wire ends to expose the copper end and unused wires with caps or wire connectors at the ends. Finally check if your fan came with nuts and connectors. Some manufacturers may use different color codes, it’s best to match the instructions that came with your fan.

How to connect 4 wires to a capacitor

  1. Connect the white wires aka neutral wires from the fan and ceiling together.
  2. Connect the green wire to your home ground wire.
  3. Connect the black wires together.
  4. Connect the blue wires together or the blue wires with the black wires to make lights. Follow the same steps for the ceiling fan without light. This will allow you to add a luminaire later without having to rewind the fan.
  5. Plug the cord back into the box.
  6. Turn on the power again and test the fan.

In this case for ceiling fans with lights, the white wire should be wrapped with electrical tape to mark that it is a hot wire and not a neutral wire. In order for the light to be controlled by its own switch, the wire connecting the switch and the fan unit requires a fourth wire, the red wire, to power the luminaire. The steps will vary slightly, you should follow the steps below:

  1. Connect the green wire to the household ground wire.
  2. Connect your white wires together and secure them with nuts.
  3. Connect the red wire on the ceiling to the black wire in the luminaire and the black wire on the ceiling to the black wire in the fan.
  4. Plug the cord back into the box.
  5. Turn on the power again and test the fan.

Causes and ways to fix broken fan capacitor

Expression when the fan capacitor fails

When the fan is damaged, the fan motor will not rotate, but the motor shaft will vibrate strongly and you will hear an abnormal sound when near the fan. Signs that a capacitor is damaged by the naked eye such as a damaged capacitor, a cracked capacitor or a broken capacitor.

The cause of the fan’s capacitor failure

Fan capacitors as well as other electronic components also have a certain service life. Capacitor failure is usually caused by the following reasons:

  • Poor quality capacitors, breakdown voltage lower than necessary, dielectric layer not working standard.
  • The actual voltage of the current is unstable and the fluctuation amplitude is large.
  • Using unsuitable capacitors.
  • The capacitor is damaged due to the number of times of charging and discharging exceeding the allowable limit.
  • Poor quality capacitors, breakdown voltage is lower than necessary

How to fix a broken fan capacitor

How to fix 4-wire ceiling fan and a capacitor

The best way is to replace a new capacitor immediately if your fan capacitor is damaged. You can do this yourself or you can take the fan to a trusted repair place. If you are knowledgeable and have professional knowledge about fans, then you can repair fan capacitors yourself at home. The author will help you remember the following items to prepare:

  • Screwdrivers.
  • Hammer, nail, knife
  • Electric tester
  • 4 types of wires
  • Electronic welding machine.
  • New fan capacitor.

Detailed steps to replace damaged capacitors:

  1. Step 1: You unplug the power cord from the plug. Next, remove the fan cover using a screwdriver to remove the screws.
  2. Step 2: Take off the fan cover and remove the damaged fan capacitor by using a soldering iron to cut off the two circuits connected to the capacitor.
  3. Step 3: Observe the parameters of the fan capacitor in use and replace the capacitor for the fan with the corresponding parameter. You use a soldering iron to connect the wires to the two circuits of the capacitor and fix it.
  4. Step 4: Finally, you do the reverse of the steps to reinstall the fan. In addition, you want the fan capacitor to have the longest use time, you should use the fan with a moderate capacity, do not let the fan run for too long, or you can let the fan run through a voltage regulator.

Usage notes to improve the life of the capacitor in the fan. During use, you should also pay attention to the following issues to ensure that the capacitor in the fan works efficiently and prolongs its life:

  • Let the fan rest for about 30 minutes to 1 hour when it has been operating for a long time.
  • Use the appropriate capacitor for the fan.
  • Use the appropriate power supply for the fan capacity.
  • Clean the fan regularly, oil the motor to make the fan operate more smoothly.
  • Place the fan in a flat and cool place.
  • Adjust the wind level just right, not too big or too small.
  • Use the fan in a dry environment, limiting high humidity.
  • Do not allow water to come into contact with the fan.
  • When repairing and cleaning, remember to turn off the fan power.

How to replace ceiling fan switches

The ceiling fan’s capacitor will also be attached to its switch. If the switch is broken, you can also fix it yourself without affecting the capacitor. Here are ways to help you fix it.

Power cut

Turn off the ceiling fan breaker to disconnect the power. Hold the voltage detector out of contact with the ceiling fan’s wall switch and lean against the fan head where it attaches to the ceiling. The detector will indicate the presence of electricity by flashing and beeping.

Clamp the box with the fitting

Find the switch housing on the ceiling fan just below the fan blade. The switch housing also holds the luminaire if you’ve already fitted the luminaire to your fan. Find the screws around the edge of the case close to the bottom. Remove these screws to remove the switch box cover or luminaire to access the fan switch.

Electrical test in voltage detector

Hold the non-contact voltage detector next to the conductor inside the switch housing to make sure you have disconnected the power from the ceiling fan before proceeding. Remove the two connectors that hold the white and black wires from the luminaire to the white and black wires in the ceiling fan if you’ve already connected the luminaire. Set the luminaire or switch box cover aside.

Adjust the buttons

Twist the fan switch chain guide from the outside of the case to open the four-wire speed switch from the switch housing.

Remove the fan switch from the housing.

Do not disconnect the wires just yet. Be sure to write down the wire color corresponding to the letters and numbers and the 4 terminals of the capacitor


Insert the straightened end of the paper clip into the opening on the side of the original switch holding a wire. The paper clip releases the tension holding the wire in the speed switch and then pulls the wire from the speed switch. Similarly, you will do the same with the remaining 3 wires.

Slide the corresponding wire end into the hole next to the paper clip.

Hold the wire to keep it in the switch while you pull the cardboard out of the hole. Repeat the step to install the remaining three wires.

Replace the cord

Thread the chain and thread throat of the four-wire switch through the switch opening. Slide the chain guide over the speed switch chain and screw it over the throat of the replacement switch.

Connect the wires

Wire the white and black wires from the luminaire to the white and black wires inside the switch housing. Screw the wire connectors back onto the two sets of wires if you are removing the luminaire from the ceiling fan.

Complete installation

Fit the luminaire or switch box cover to the bottom of the switch box. Secure the luminaire or switch cover with the screws you removed earlier. Finally, you turn on the ceiling fan breaker and check the operation.

F.A.Q: How to connect a 4-wire ceiling fan to a capacitor 

Why does my ceiling fan have 4 wire capacitors?

The reason a capacitor needs a lot of wires is because the capacitor has a lot of important functions that make the ceiling fan work better. This is one of the extremely important passive electronic components, they are widely used in the production of electricity. This process includes filter circuits, oscillator circuits and signal transmission circuits of alternating current. Having 4 wire cords in a capacitor will help the fan operate at full capacity, each wire will have its own function.

What are some notes to keep in mind before repairing?

Ceiling fans use an internal fan capacitor to control the speed of the fan blades. You choose to operate the propeller at high, medium, or low speed, or stop the propeller from spinning by pulling the chain attached to the side of the fan. Because these 4 speed switch wires are made of plastic, the switch is often broken at the throat or the chain pulls from the inside of the switch. Before replacing a capacitor, make sure that all of your connectors will fit together and that there will be no working power.

How to know the wrong wires to the capacitor?

For ceiling fans, after connecting the wires to the capacitor, but turning counterclockwise or turning on no wind, you need to remove and reinstall.

The capacitor has the effect of deflecting the magnetic field, providing a large voltage when the fan motor starts. Therefore, if the wrong capacitor is installed, there will be signs of deviation, swelling or broken plastic outer shell.

What are the important parameters of the capacitor?

Usually, when buying and using ceiling fan capacitors, people often pay attention to the “µF” unit, the “mf”unit is also quite new. The author will help you to see the specifications for yourself to choose the perfect capacitor for your fan.

+ F: microfarad (1 F = 10^-6 farad)

+ 1mf = millifarad ((10^-3 farads)

Fan capacitors have many types and depend on the manufacturer, but I find the most commonly used and sold types are 2mf capacitors and 3mf capacitors.


Hope the information on how to connect a capacitor with 4 wires and how to fix the switch can help you.

Toby Nwazor

Toby Nwazor is a serial entrepreneur, a success coach, a business development consultant, a strategist, a motivational speaker, and a freelance writer. He writes on other cool platforms like Entrepreneur magazine,, Good Men Project, and Business 2 Community and author of website articles . He is the founder of My Startup CEO where he gives kick-ass motivation and provides helpful tips for start-up business success. Follow him on Twitter, and Like MSC on Facebook

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