How To Wire A Light Fixture With Red, Black, and White Wires

So, you open up a new light fixture and end up looking at a pile of black, white, and red wires!

In this guide, you will learn:

  • How to install a light fixture when there is 3 different colored wires!
  • Why there might be a red wire in the fixture
  • The best way to compare wire colors of the light switches and fixtures 
  • And more!
how to wire a light fixture with red black and white wires

If you have a basic understanding of electrical systems and how to make electrical connections correctly and safely, you can probably use this step-by-step guide to help walk you through wiring your red wire light fixture. 

If you run into complications and are unsure how to move forward with your project, this is a good time to stop and call in a professional to come finish up. Safety needs to be your top priority while working on electrical projects!

You can also read the building code on light fixture wiring from the International Residential Code handbook but the NEC and local codes have priority in the USA.

Keep reading to learn the 5 steps on how to install a light fixture with red, black, and white wires!

Red Wires In A Light Fixture Can Mean A Few Things

When working on electrical projects in your home, especially if it is an older home, you can run into many different scenarios.  When it comes to having a red wire in a light fixture box, it can mean a few different things:

  • A ceiling fan with a light may have been in place before, and the light and the fan may have been controlled by two separate switches.
  • There may be 3-way switches in the circuit (Here is my full guide on wiring a 3-way switch)
  • There used to be smoke detectors hooked in series. The red wire is used to interconnect them.  
  • The red wire is going to the switch while the black wires are passing through taking power to a different location. 

The last is a common practice, but it is not a strict standard for electricians to use this color scheme. Be sure to verify your wiring before assuming anything! 

Verifying Your Lighting Circuit

The best way to verify how your lighting circuit is wired is to pull the cover plates off all the switches involved and remove them from the boxes. Do not unwire them!

This allows you to be able to compare the wire colors going to your switches and the wire colors that are in your light fixture.  You may want to shut the power off just as a safety precaution before pulling the switches out of the box. I invite you to read my guide on wire color identification here.

It is very important that you do not hook the red and the blacks together if they aren't already! Doing so can cause you to trip a circuit breaker and potentially do damage to your outlets and the integrity of your house wiring.

how to wire a light fixture with red black and white wires

Supplies & Tools Needed

  • Voltage Meter - Used to verify power is off 
  • Screwdriver - Used to make wire terminations, remove and install outlet covers
  • Wire Strippers - Used to strip the insulation off the individual wires
  • Electrical Tape - Used to wrap the outlet around the termination screws as another layer of safety   
  • Extra Wire - Used to connect multiple wires together while being able to land on the switch
  • Wire Nuts - Used to tie multiple wires together

5 Steps To Wire A Ceiling Light With White, Black, And Red Wires

  1. Turn Power Off
  2. Remove Old Light Fixture
  3. Install New Light Fixture
  4. Verify Connections
  5. Turn Power On and Test

Step 1 - Turn Power Off 

Before beginning, it is important to turn the power off and verify it is off using a voltage tester.  

You will place one probe on the hot wire and one on the ground wire. The meter should read zero.

Electrical panels can sometimes be mislabeled so it is important to always test before touch! We recommend reading this guide from Washington University for more details on electrical safety in the home.

Step 2 - Remove Old Light Fixture  

Remove the light fixture.  

Using your screwdriver, loosen the terminating screws enough that you are able to unhook the wire from the screw.  Or remove the wire nut to separate the wires.  

Before unwiring it, it is a good idea to snap a quick picture with your phone.  This will give you a schematic on how to wire it back up.

It can also be useful to label the wires with colored markers or tape to help keep all the wires straight; especially when there is a box stuffed full. 

You want to be sure to wire the new fixture back in the EXACT same way it was unwired.

Make sure to note of any other wire connections in your box; while working in the box, it is possible to pull the other connections apart.

Read Also >> How To Wire A Standard Light Switch?

Step 3 - Install New Light Fixture

Install the new light fixture and connect the correct wires.

When install the new light fixture, be sure to pull up the picture you snapped to reference how it was wired.  

If you have a red wire coming from the light switch, this will hook on the brass screw or it will get wire nutted with the black wire coming from the fixture.  The white wire will land on the silver screw or use a wire nut to tie it together with the other neutral wires.  Any green or bare wires will be terminated on the green screw or again will be tied together with a wire nut.  

If there are termination screws, make sure the hooks on the end of the wires will be able to slide under the screws.  If not, use the tip of your wire strippers to straighten the wire and then make a new hook.  

If you are unable to straighten the wires enough to get a good connection and you have enough wire, snip the exposed wire off. Then strip about 3/4 to 1 inch of insulation off. Again, using the tip of your strippers, pinch the end of the wire and curve it around the make a hook. 

When using wire nuts, make sure all the wires are nice and straight. Each wire should have roughly the same amount of insulation stripped off.  This helps to ensure that all the bare wire will be covered by the wire nut.

Step 4 - Verify Connections 

Verify all the wire connections, whether they are screws or wire nuts.

Double-check to make sure ALL screws are tight and the wire will not move underneath it.  

When using wire nuts, give each individual wire a good tug and try and pull it out from the wire nut.  If any wire pulls out, you will need to redo your connection.  

Loose connections can cause hot spots or lead to issues with passing power.  Hot spots are capable of causing a fire.

Read Also >> How To Wire A 220-Volt Well Pressure Switch?

Step 5 - Turn Power On and Test

Once all connections are checked, fixtures installed, and covers reinstalled, it is safe to turn power back on to your circuit.  Flip your light switch and watch your lights come on!

Frequently Asked Questions

What Do I Do With The Red Wire When Installing A Light Fixture?

There are different reasons there would be a red wire in the light fixture.  The most common use of a red wire is to run from the switch to the light. 

Does The Red Wire Go With The Black Or White?

It depends on the situation.  Most commonly, the red wire is used as a hot wire.  Never hook wires together unless you know for sure where they go. 

Why Do I Have A Black, White, and Red Wire?

Red and Black wires are typically used as hot wires.  White wires are neutrals.  A red wire could be because there are 3-way switches in the circuit, or it is being used between the switch and the light.

Do I Connect The Red Wire To The Black Wire?

You should never connect two different colored wires together unless you know for sure where they are coming from and where they are going.  Black and red wires are commonly used as hot wires or current carrying conductors.

What Is The Point Of A Light Fixture With Red, Black, and White Wire?

The point of having a red wire along with a black and a white, is sometimes it is necessary to use the black to carry power to a different location so the red is used to control the light from the switch.  This saves you from having to run a whole new wire.

Does The Red Wire Connect To Black Or White?

Since the white wire is neutral, you should never connect a red wire to the white. However, you may connect the red wire to the black since they are both hot wires.

Can I Connect Red And Black Wires Together?

Yes, it is sometimes feasible to connect a red and black wire together for a variety of reasons such as connecting smoke detectors, wiring back to a switch, a 3-way switch circuit, and other reasons.

Read Also >> How To Wire A 3-Way Light Switch?

Final Thoughts

Never assume, just because your light switch is off, there is no power in the box you are working on! 

Take your time and make sure you understand where the wires come from and go to ensure everything is hooked back up safely and the correct way! 

If you ever find that you have gotten in over your head working on an electrical project in your home, be sure to stop and call your local electrician for help! It's always better to be safe than sorry! 

I hope you enjoyed this Home Inspector Secrets guide!

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