Checking Christmas Tree Lights

We thought we would give you a quick rundown of the best way to test whether your Christmas tree lights are working because they are broken, or if it is just a faulty bulb, by using an electrical mains tester screwdriver.

While the lights are in storage during the rest of the year little elves get tangled up in the wire and shake the bulbs until they break (or at least that is what we believe happens).

So do you work your way through the lot, to find the faulty ones or throw them out and buy new ones?

We recommend that you follow this quick guide to mending your Christmas lights before you go any further.

Testing the Connections and Wiring in Fairy Lights

1. Unpack your bulbs and plug them in to test they work, before you put them on the tree.

When they don’t work

2. Check the fuse and wiring in the plug. You can see how to wire a plug and test cables here

3. Test the bulbs – start at the plug end and check to see each bulb is firmly in its holder.

When you get to a loose one they should all come on (it’s always the last one, whichever end you start!)

If that doesn’t work, it is likely that a bulb has blown. This is where your screwdriver comes in.

4. Undo each bulb in turn and test the connector with your electrical screwdriver. (See more in our project page about Christmas lights). Where the LED indicator light in the screwdriver comes on without flickering there is a good connection.

If the LED comes on for some of the bulb holders then stops, the bulb connector or the wires feeding it may have been damaged. The easiest and often cheapest option here is to buy new lights, although you can replace bulb-holders or even bypass the faulty bulb-holder, if you know what you are doing. Again you can visit our project pages for more information.

You can buy all the tools for this, and other projects by clicking on the image below, which will take you to our DIY Superstore.