How to Repair Christmas Lights

It’s the same story every year. You spend hours detangling and hanging your Christmas lights, but when it’s time to light them, they flicker on and off or light up only halfway. Suddenly, you find yourself spending the whole evening trying to figure out why your Christmas lights won’t work.

 To save you hours of frustration, we’ve compiled a guide on the most common problems and solutions on how to fix your Christmas lights once and for all and the tools you’ll need to do the job right.

1. Defective or Broken Bulb

If you plug in your lights and find that only one bulb is blown out, but the rest of the string works, you’re in luck. Swap out the blown bulb for a new one. But if a specific section of your lights isn’t working, it could be due to a bad bulb or a broken connection between the bulb and the socket.

Unplug the lights from the power source and work your way down the string from the first unlit bulb, making sure to check every bulb in the chain and replacing defective and broken bulbs with new ones. If the whole string isn’t working, you’ll have to check all the bulbs. You can use a permanent marker to keep track of your progress.

Before inserting the bulbs into the socket:

  1. Check the wires at the bulb base to ensure they are wrapped properly.
  2. Be careful when removing the bulbs since some bulbs screws in, and if you twist at an angle, you can break them.
  3. Use your fingernails or find an appropriate tool to separate the bulb base from the socket gently.
  4. Once you’re done replacing all the non-functioning bulbs, plug in the lights. Your Christmas lights should be working.

2. Blown Fuse

A blown fuse is the most common cause of broken Christmas lights, especially if the entire string of lights isn’t working. To replace a fuse, take the plug and pry open the plastic part with a flathead screwdriver or small pliers set. Then gently remove the two fuses and inspect them.

Good fuses have an unbroken strand of wire running in between. Most Christmas lights come with replacement fuses, so take the new ones, plug them in and close the cover. If you don’t have replacement fuses, you can get them at most home improvement stores. To ensure you get the right fuses, it’s better to take the strand of lights with you.

3. Circuit Overload

If you’ve thoroughly checked your lights for broken bulbs and have determined the fuse isn’t the problem, then your light strands could be overloading your electrical outlet. Although Christmas lights are designed to be strung together, linking up too many on a single chain can overload your power outlet.

To resolve this issue:

  1. Consider dividing your lights among two or more power sources to distribute the electrical current evenly. You should also check if your outlet can handle your light’s wattage demands.
  2. Check your breaker box to find out the amp capacity of your outlet.
  3. Multiply the amp value on your outlet by the number of volts shown to determine your maximum wattage. If you realize that you’ve exceeded the max wattage, reduce the number of strings connected to one outlet.

4. Corroded Socket

A corroded socket could be responsible for your bulbs not working. With time and use, the socket contacts become corroded of filled with grime and dirt, preventing the bulb from connecting properly to the socket. This disrupts the power supply to the bulb, causing your lights not to work.

To get your lights working again, use a small scratch brush or file to clean the socket’s wire contacts. Once done, get a new bulb, insert it into the socket, and then plug in your lights.

If this doesn’t work, then the bulb socket might be broken beyond repair. But don’t worry, you don’t have to buy new lights. Remove the bulb socket from the light strand using a wire cutter. Then strip the wires, twist them together, and insert them into the twist-on wire connector. To secure the wires, turn the connector until it’s secure, and you can pull on it without it falling out.

Tools You Will Need To Fix Your Christmas Lights

Unless you’re replacing a single broken bulb that you can easily identify, determining the source of the problem killing your lights is tedious. These Christmas lights repair tools and Christmas lights tester tools will help make the process easier so you can get back to celebrating your holidays.

Best Overall

Fix Your String Light Decorations With A Squeeze Of The Trigger 7.4 Check Price

Best Mid Range

Ulta Lit Keeper LED Light Set Repair Tool 8.2 Check Price

Cheaper Choice

Klein Tools NCVT-2 Voltage Tester 9.2 Check Price

KAIWEETS Digital Multimeter TRMS 6000 9.4 Check Price

IRWIN VISE-GRIP Wire Stripping Tool / Wire Cutter, 8-Inch 9.4 Check Price

1. Light Keeper Pro

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BUNDLE INCLUDES: LightKeeper Pro Holiday and Christmas Tree Light Repair Tool with 50 Spare Bulbs
3-WAY BULB PULLER: This Light Repair Tool helps release tight and stubborn bulbs from their sockets...

Whether it’s a single bulb or the entire dark string, the Light Keeper Pro can help you to quickly extract the defective bulb and replace it with a new one. It sends an electrical pulse through the bulb, clearing the shunt and allowing electricity to flow again. This completes the circuit with the other bulbs lighting up the entire string. It also has a voltage detector that lets you find where the electricity flow stops. The set comes with spare bulbs.

2. LED Keeper Repair Tool

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Bulb and fuse tester tests indoor and outdoor replaceable led lights
Includes 2 bulb replacement pods and 2 place markers
One 9 volt battery are included

If you have LED Christmas lights, you might want to get this Christmas lights repair tool. It comes with a bulb and fuse tester that lets you find which bulbs or sockets are faulty. It also has two place markers to mark the start point and endpoint of the section of your lights that won’t work.

3. Klein Tools Voltage Tester

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Voltage Tester automatically detects and indicates low voltage (12-48V AC) and standard voltage (48-1000V AC) allowing broad application
Non-contact detection of standard voltage in cables, cords, ...

If you prefer something more simple, this voltage tester can determine if the voltage is going to the bulb. Once you find the one without voltage, you can replace it and see it solves the problem.

4. KAIWEETS Digital Multimeter

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WIDE APPLICATIONS - KAIWEETS digital multimeter features 6000 counts auto-ranging for accurate measurement of AC/DC voltage, AC/DC current(DC is the default), resistance, continuity, frequency, cap...

The KAIWEETS multimeter can help you check the circuitry and fuses and test for bad bulbs. This tool also doubles up as a non-contact voltage tester.

5. Irwin Vise-Grip Wire Stripping Tool

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Wire cutter with induction hardened cutting edge stays sharp longer
Strips and cuts 10-22 AWG
Pliers style nose allows wire stripper to pull and loop in wire
Bolt cutter cuts bolts to size and leav...

The Irwin wire stripper is an easy-to-use tool that lets you cut and strip wires so you can easily repair your Christmas lights.


Fixing Christmas lights is not as challenging as you might think, and you certainly don’t need extensive technical skills. With the right Christmas lights repair tools and knowledge, you’ll have your lights working in no time.