Mini Lights – Changing a Fuse

by | Oct 5, 2022

“Help! My Christmas lights set has gone completely out!”

How do I change a fuse in Christmas lights?

If an entire set of mini lights has gone out, more than likely, you’ve blown a fuse. This commonly happens when too many mini lights sets are connected in series.

In most sets of Christmas lights, there are one or two fuses located in the male plug. If too many sets are connected in series, they will draw more current than they can handle safely, and the fuses will “blow.” Unplugging the sets and replacing the fuses should restore them.

Replacement fuses are usually packaged with replacement bulbs in tiny little bags and taped to the Christmas light strings near the male plug. Be sure to collect these little bags into labeled bags for the future.

Using a small short flathead screwdriver, slide back a little door on the male plug and use a small flathead screwdriver – the kind used to open little screws on battery doors – to gently pry out the burned-out fuse and gingerly install a new fuse.

If replacing the fuse does not solve the “lights-out” issue, an alternative issue might be an unseated bulb. So, if your fuses are OK, look for a damaged bulb base or unseated bulb. If a bulb is damaged, use one of the included extra bulbs as a replacement.

See the links to videos about changing fuses in Christmas lights below.

How can you tell if a Christmas light fuse is blown?

If all of a set of Christmas lights has gone out, more than likely, a fuse has blown. If just a few lights are out, the issue is not the fuse. To confirm if the fuse is blown, open up the fuse compartment door in the male plug of the light string, remove the fuse with a small flathead screwdriver and see if the hair-thin fuse wire is broken. The fuse may have a dark residue inside the glass if the fuse is blown.

Why do my Christmas lights keep blowing fuses?

Fuses in Christmas lights blow when too many sets of lights are connected end-to-end. Fuse blow to protect users from plugging too many light sets together and creating an electrical hazard. After replacing the fuse, plug together only the maximum number of light strings or less than is indicated in the light set’s specifications.

Do Christmas lights need both fuses?

Remove both fuses. Look for metal contacts at each end of both fuses. If there are two sets of contacts, both fuses are required. If one fuse has no metal contacts in the fuse compartment of the male plug then it is an extra replacement fuse.

Can you change the fuse in a string of Christmas lights?

Most (but not all) Christmas lights have a fuse or set of fuses installed in the mail plug. Slide back a little door using a small flathead screwdriver into a slot or depression. Some male plugs will have a screw-out fuse assembly between the prongs. Using a small screwdriver to unscrew the assembly and replace the fuse.

Here is a quick video on where to find and how to replace the fuse in your set of mini lights. We’ve also included a quick blog post about stringing too many Christmas lights together.

Changing a fuse in Christmas Lights
Mini Lights - Changing a Fuse 2

Originally published on November 4, 2011 3:30 pm. Updated October 5, 2022.

Recent Posts

Get this Look: Multicolor Parade Lights

Get this Look: Multicolor Parade Lights

Materials 12-volt Multicolor LED light strings Zip ties Painter's tape No need to use and inverter for a parade. This project uses LED light strings that have a male accessory plug compatible with most vehicle accessory outlets. (Or in older cars, the cigarette...

read more


Submit a Comment

Your email address will not be published. Required fields are marked *

Related Blog Posts

Get this Look: A Multicolor Traditional Christmas

Get this Look: A Multicolor Traditional Christmas

We love Wade's traditional outlined roofline for Christmas. Using triple-dipped glass bulbs, the color is rich and nostalgic. Standard glass bulbs have two coats of paint. As the name implies, triple-dipped have three resulting in rich colors at the tradeoff of being...

read more
Top 10 Christmas Lights Questions

Top 10 Christmas Lights Questions

We've been answering customer questions for 16 (almost 17!) years. Here are a few of the technical questions we hear most often. How do I light a really large tree? This project provides a great reference for large tree projects....

read more
Get This Look: LED Trees!

Get This Look: LED Trees!

We love this festive family of wire-frame and (and one natural) Christmas trees! Jim W. had this to say about them: Excellent products & Quick DeliveryLED 5 mm lights were excellent for my Christmas project. Green wiring also contributed to the nice...

read more
Video: What is the “mini” in minilights?

Video: What is the “mini” in minilights? What is the mini in mini lights?The description "mini" refers to the relative size of the small glass bulbs in Christmas tree lights compared to larger C7 or C9 bulbs. These three bulb sizes were the most prevalent when Christmas lights...

read more
Green 12-volt LED Christmas Lights on Green Wire

Green 12-volt LED Christmas Lights on Green Wire Transcript This is a set of 12-volt DC Christmas lights on green wire. You can see that there is a light section which is plugged into a 15-foot extension section that plugs into an accessory outlet. Now, this light section has 20 green...

read more