Shorten Christmas Lights

In this tutorial we will show how to shorten string Christmas lights.

Shorten String Christmas Lights

Have you ever found yourself in a situation while decorating for Christmas where you need a shorter string of Christmas lights? Maybe you need to finish a small section on your roof or you would like to add lights to your fireplace mantle but don’t need 30 feet to get the job done.

Today we are sharing how to shorten string Christmas lights to the exact length you need. Follow the simple steps and the second diagram below and you will be able to shorten string Christmas lights in no time.

Important: Use caution when working with exposed wires! Exposed wires can shock you. Don’t plug in the lights until you have all the exposed wires covered with wire connectors and always use outdoor/waterproof wire connectors if your lights will be outdoors. All tips below are based on our experience and if you use any of the techniques shown below, you are doing so at your own risk.

How to Shorten String Christmas Lights

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DIRECTIONS WATCH

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DIRECTIONS READ

Shorten String Christmas Lights

One way to determine how the lights are wired is to completely remove one of the bulbs. If all or a section of lights turns off than the lights are wired in series. If all the lights remain on then most likely the strand is wired in parallel.

Lights Wired in Series

Shorten String Christmas Lights: Wired in Series

Most mini christmas lights and LED christmas lights are wired as multiple sections of wired in series. Start by locating both sides of each series section of lights that turn off when a bulb is removed. You should see that the christmas lights change from having 3 wires to 2 wires then changes back to 3 wires.

Shorten String Christmas Lights

The best way to shorten lights wired in series is to remove an entire series section of lights by cutting lights apart where there are only has two wires, with the lights unplugged. Then, simply cap each of the two cut wires with a wire nut. If the lights go outdoors be sure to use outdoor/waterproof wire nuts.

Risk of removing individual lights from lights wired in series

If your goal is to remove one or two lights off a strand wired in series it is possible but not ideal. Christmas lights wired in series spread 120 volts coming out of the plug across all the lights. Each light that is removed increases the voltage to all the remaining bulbs.

As you can see, removing a few bulbs isn’t a huge deal but remove too many and risk burning out all the lights.

Shorten String Christmas Lights

Notice as the bulbs are removed and the volts/light increase the lights get brighter

120 volt / 40 bulbs in series = 3 volts/bulb
120 volt / 35 bulbs in series = 3.4 volts/bulb
120 volt / 10 bulbs in series = 12 volts/bulb

How to remove individual lights from lights wired in series

Shorten String Christmas Lights

1. With the lights unplugged, cut the two wires that enter the last light in the series strand.

Shorten String Christmas Lights

2. Use wire cutters to strip the ends of the two wires cut in the previous step. Twist the two bare wire ends together.

Shorten String Christmas Lights

3. After twisting the wires together secure with a wires nut. Then, cut the third wire to match the length of the other two wires and cap it with a wire nut.

Wire diagram for series Christmas lights

Shorten String Christmas Lights

This diagram shows how Christmas lights wired in series are wired. There are three different wires. Each colored line represents a different wire. The blue line connects all the lights together in series and supplies power to the light bulbs. The yellow and red wires are both connected to the blue line on either side of the light bulbs.

Shorten String Christmas Lights

The diagram above shows the CORRECT way to connect the spliced wires. By connecting the wires this way, the lights will turn on when you plug it in. As you can see the blue wire (the wire connecting the lights) must always be connected to one of the loose wires.

Shorten String Christmas Lights

The diagram above shows another possible way to connect the wires. If you connect the wires this way the light bulbs are only connected to one side of the power and they will not turn on. As you can see in the diagram, the red wire is not connected at all. You must switch the wire coming from the light bulb to connect to the other loose wire.

Shorten String Christmas Lights

This diagram shows that if you connect the wires this way it will short circuit and throw the breaker for the outlet. Don’t attach the two loose wires together. Only one loose wire and the wire coming from the light bulbs should be connected together.

Shortening Christmas lights wired in parallel

The lights are designed so each bulb receives all 120 volts and each bulb has a direct route to power, meaning they can be cut to any length without overpowering and burning out bulbs.

Shorten String Christmas Lights

With the lights unplugged cut wires between the bulbs and cap each end with wire nuts.

We hope this helps you adjust the length of your Christmas lights so you can now you hang up you custom length string Christmas lights! Now that you know how to shorten string Christmas lights, you can fill in any small gaps of lights on your roof or create custom length string lights to decorate with in your home.

21 Thoughts on “Shorten String Christmas Lights”

  • I’d like to extend the distance between bulbs to go from one section of the house to another without having to unscrew bulbs. I’m a bit OCD and it drives me nuts to see the empty sockets running across my roof. My lights are LED and have 3 strands (assuming they are series) of wire…do you know where I can buy 3 strand wire? I’ve found 2 strand but again…OCD.

    • You do not need “3 strand wire” to extend them. Find a picture online of lights in a *Parallel* circuit, which is what you have. You only need to connect two wires, as the 3rd wire is already in a T-connection with the bulb and other power/ground wire. With that being said, you would need to connect the 2 wires together and might need to extend the 3rd wire by itself.

  • I found some black covers that fit over mini lights so you can reduce any number of lights in a string. Only problem is then fixing a place for the blacked out lights. Most useful when removing more than 1 or 2 lights.

  • I’m looking to shorten a light stand to about only 5 lights but the C9 bulbs ate too big. How can I know if the lights I’m looking at run in a series or not?

  • Be sure to twist the wires tightly. Make sure no loose wire strands are sticking out. It sure doesn’t hurt to wrap the wire nuts with some electrical tape to make sure they don’t get knocked off. When it comes to house current, it is good to be double safe! Be careful! XXXOOO!

  • WONDERFUL, thank you!!! Last year my son did the lights and we ended up with a giant clot of ganglion wires over the front door – it looked far more Halloween than Xmas, but we were too lazy/busy/disinterested to do anything about it but laugh. This year will be somewhat different, thanks to you 🙂

    • Hi Jean, That is a great idea for another video. If you cut the lights where there are only two wires adding a plug is pretty simple. If you google “add plug to lamp cord” there will be lots of information that is similar.

    • As long as you cut it in the middle as Was instructed there should only be Two cut wires on the strand with out a male plug. If you have an old set of lights that you no longer require you could cut the Male plug end off leaving a workable length of wire and strip the wires on both ends and wire nut them together just be mindful of polarity. And now you would have Two separate sections of lights.

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