How To Test Christmas Light Bulbs

Pull out one bulb at a time, and stick a piece of folded up foil into the bulb socket. If the lights come on, you know that's the bad bulb. If they don't, put the bulb back in and move on to the next one. If you don't have any replacement bulbs, you can leave the foil in until you do.

Can you test Christmas light bulbs with a multimeter?

To check which Christmas light is out without a tester, you place one multimeter probe into the first bulb hole and place the other probe into another bulb hole. If the multimeter reads other than 0, then there is a bad light between these two bulbs.

How do you test Christmas lights with a tester?

While you tap what I'm gonna do is I'm gonna take this light. Out. I'm gonna slide the wire. Down.