Common Christmas Light Fixes

Many people experience the same annoyance every holiday season: lights that don’t work. Fortunately, burned-out Christmas lights is a common problem you can solve with a little time and patience. Best of all, fixing these troublesome lights means you don’t have to throw them out and purchase a new set, leaving extra room in the budget for other holiday expenses.

Step 1 - Diagnose

There are a few reasons why Christmas lights go bad. Determining if a bad bulb just needs to be replaced or if the malfunction is caused by something else is the first step in repairing the lights. Modern lights are made so that one bulb won’t disrupt the entire circuit, so replacing a few bulbs might do the trick. The telltale sign of a bad bulb is a section that won’t light up or a few bad bulbs throughout the string.

Step 2 - Check the Fuse

If the entire string is dead, then check the fuse. Blown fuses are the most common cause of malfunctioning Christmas lights. With the lights unplugged, simply pry open the plastic fuse covering (typically located on the plug) and remove the fuses. The fuses should be transparent and contain an unbroken wire. If the wire is detached or the fuse is black, then it needs replaced.

Step 3 - Replacing the Fuse

You may find replacement fuses in the original box, or you can take the blown fuse to a local hardware store to get the exact replacement. Using a fuse with a higher rating is a huge fire risk and should be avoided at all costs. Further, some LED light strings only use one fuse, but contain a backup in the fuse compartment.

Step 4 - Installing the Fuse

With the new fuse in hand, simply pop it in the old slot and reinstall the cover. The lights should power on after the new fuse is installed. If this does not work, then try a different outlet. Sometimes, the house blows a fuse or trips a circuit in the process. If none of the above steps have worked, proceed below for more Christmas light fixes.

Step 5 - Testing Bulbs

Malfunctions in the manufacturing process can kill an entire string of lights, even if only one bulb is dead. Sections of the string can also go dark because of one bad bulb. Whatever the case, you can test the bulbs using an inexpensive tool, like a continuity detector. Before you start testing each bulb, ensure they are all tight and that none of them are visibly damaged. Sometimes, a loose or broken bulb is the culprit. Each tester uses a different method to detect bad bulbs, so remember to follow the directions in the manual.

Step 6 - Cleaning Bulbs

When a bulb burns out or gets accidentally stepped on, it can leave behind debris in the socket. Use a small set of pliers to remove any big chunks from the socket and clean any corrosion with a scratch brush. When inspecting a string for bad bulbs, it's always a good idea to check the connections on each bulb to avoid corrosive buildup. Not only will this get your lights up and running again, but it can also extend their life expectancy.

Step 7 - Bad Wiring

In rare cases, replacing the fuse and bulb is not enough to fix a string of lights. Sometimes, the socket may have been damaged beyond repair, especially if it was stepped on or accidentally cut. If that is the case, you will need to replace the socket with a new one to get the lights running again.

Step 8 - Install a New Socket

Using wire cutters, remove the bad socket from the string and strip away about 1/2 inch of insulation from both the existing and replacement socket. Twist the exposed wires together with a cap and pull on it to make sure the wires are secure. Plug in the lights to test your work and use a sealant to keep moisture out of the cap.

Store and Care

Dealing with bad Christmas lights is inevitable, but there are some things you can do to ensure they last longer. When you take down the lights, plug them in and make sure they are all still working. Also, ensure the lights don’t bang together in storage and avoid jamming them in a tightly wound coil.