How to Replace the Fuse on a Christmas Light String

Keep your Christmas tree lit by learning how to replace light-string fuses.

Most strings of Christmas lights have a small fuse box in the plug area. The fuse is designed to prevent a short circuit or overheating that could lead to damage to the lights -- or the lights causing damage to your house. A common reason for blowing a fuse on a string of Christmas lights is plugging too many lights together. The safe threshold for Christmas light strings is three, according to the Christmas Lights Advice website. Other causes of a blown fuse include power surges or defective fuses. To get your lights twinkling again, you just need to change the fuse.

Things You'll Need

• Flat-head screwdriver
• Replacement fuse

Instructions

1. Unplug the Christmas lights. Even if the fuse is blown, you don't want the lights plugged into the outlet.

2. Open the fuse box on your Christmas tree light string to confirm that the fuse is blown. You can see the fuse box clearly marked on the light string plug. Slide the top of the fuse box off with pressure from your thumb. If you cannot move it with your thumb, use a flat-head screwdriver to gently push the door open.

3. Examine the fuse to see if it is blown. A blown fuse will have a black residue evident inside the glass chamber. If there is no black residue, the blown fuse is in a different string.

4. Pop out the fuse by gently placing the flat-head screwdriver under the fuse and apply pressure upwards.

5. Wipe the fuse area clean with a dry towel to clean out any excess debris.

6. Place the new fuse over the area where it will be installed. Press down gently over top of both contact areas with two fingers until the fuse pops into place.

Tips & Warnings

• There are three ways you can get extra fuses for your Christmas lights. The first is to use the spare fuses that came with your lights in a small plastic bag. The second is to check the fuse box on the light string to see if a spare fuse has been placed in there. If neither of those options are available to you, then take the blown fuse to an electronics store to get a proper replacement.

• Make sure the light string is unplugged from the wall and any other light strings before you start working on it.

• Do not apply pressure to the glass part of the fuse when removing it or putting the new one in. Apply all pressure to the metal contacts.

References

• Christmas Lights Advice: How to Replace a Fuse
• Christmas Decorations Gift Store: Christmas Tree Decorating With Lights

Resources

• The Money Pit: Christmas Light Repair