I have a set of regular Christmas lights, and one half of the set doesn't work.

Can the half that doesn't work be removed and somehow join or solder the two remaining wire ends?

The last working lightbulb has two wires going in, and only one wire going out. There's a third wire, but it goes past the lightbulb.

enter image description here


In a way, this is kind of like asking, "Doctor, I got a sliver in my finger, what do I do" to which he replies, "get into the office immediately, we need to amputate at the shoulder or higher"

I'm just kidding :)

But YES, you can, however, you really should skip the operation. Pulling the sliver or repairing the fault is more economical, but time consuming. Light sets are so inexpensive today its often worth it to buy a new set.

I tend to keep a few laying around that I can use for spare bulbs. Many bulbs nowadays can blow and still allow the set to work, but this isn't entirely perfect. A bad bulb, or a poorly seated bulb, or a broken bulb lead, or a lead not centered well, or a wire pulled out of the socket is usually the culprit. You can bulb swap unknown bulbs 1 at a time with a single socket you know is working.

While you can rewire a set, you'd now have to tape it, and also ensure you arent increasing the voltage so much that you overpower the remaining bulbs and blow them too. 100 light sets are usually using bulbs for 100 light sets. Turn that into a 50 or 25, and the voltage goes up.

Not worth messing with,and if it is, its more useful to keep the set intact.

The 3 wire part is leading the hot and neutral to another section of the lights, so if it is a 100 set, it is already 50 and 50 :)

Decide if you want the outlet, measure it from end to end with an ohmmeter, and cut and repair the last socket with the outlet if being used, re measure everything before plugging it in, and be sure to keep hot hot, and neutral neutral.

Dont both attempting it if you arent able to do this.


Most lights are actually low voltage and that's why when 1 goes out a whole section of lights go out. I would caution againts changing the number of lights. My wife purchased a short string to put all my hallmark moving ornaments on, not realizing these lights were like 15v as the standard ones were 3v - fried every one of them collected over 20+ years. If the voltage is wrong they will flash and be done.


Yes - most Christmas lights are actually multiple sets wired in parallel.

That third wire you mentioned likely starts at the first bulb, then goes right the way down the string without touching anything until it gets to the first bulb of the second series.

They say a picture speaks a thousand words: Diagram of christmas lights showing wire to be cut running the length of the set

If it's the half nearest the plug that still works, cut the purple wire at the very first bulb (nearest to the plug). Unwind it, leaving one wire (black in the picture) connecting the two halves of the set.

Cut the black wire where it comes out of the last (working) bulb, making sure to seal any exposed wires with electrical tape.

  • Hello, and welcome to Home Improvement. Great answer: thanks. My one concern would be using electrical tape to seal connections; it isn't made to mechanically join wires, especially those that will be flexed. Use wire nuts, and THEN cover with electrical tape. – Daniel Griscom Dec 25 '18 at 13:37
  • @DanielGriscom There wouldn't be any wires to join, OP wanted to remove half of the set rather than tack another set on. Where some sets would have a junction box, OP's seems to have the "second" set connected within the last working bulb's housing. I was referring to taping the redundant wires that would be left poking out of the first and last bulbs after cutting, rather than joining any together. Perhaps I could've made that more clear, thanks for your comment. – Dave S Dec 26 '18 at 17:12
  • Ah, yes. You provided an excellent diagram; I should have looked more closely, and noted that there was no female socket at the end, which would have required wire nuts. Thanks. (I'm still not a big fan of electrical tape...) – Daniel Griscom Dec 26 '18 at 18:19

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