Basic electrical question... Installing a light fixture

I’m super confused, help!

  • I’m installing a new light fitting from John Lewis
  • I’ve connected all the wiring into wago blocks and am confident in all of the connections
  • when I connect in the old pendant into the new wiring setup, I get 240v at the bulb end
  • when I connect the new light fixture I only get ~25v at the bulbs which isn’t enough to do anything
  • I have continuity between the ends of the wires and the bulb terminals

So, I’m losing ~90% of my voltage it seems over the light. It seems to me like the light they’ve sent is faulty but I don’t have super high conviction as a total electrical noob. I’ve also had to cut the cables and chain and stuff down to get this far so you feel you need to be sure before sending it back!

Any advice? Other tests I can do?

Do you have a link to the product you bought?

Just to clarify: You have an old ceiling pendant, you get 240 V. When you remove that, and install the new fixture in place of the old pendant, you only get 25 V from the bulb terminals? Is it just a basic light fixture with wires going straight to the bulb terminals, or is it some kind of LED or fluorescent device with a transformer/ballast in the mix? Can you confirm the voltage at the Wago blocks?

The only reason I can think of you getting 25 V from the bulb outlet is maybe you’re getting some kind of phantom voltage from another device somewhere on the circuit. Are you sure you’ve turned the circuit back on? Check the trip switches maybe?

The new light is the same as the chandelier photographed above. We have one in the room already I installed a few months ago and I am now putting another up

Where I’m putting it up, there was until recently just a simple pendant which was wired with a ceiling rose

I’ve taken the ceiling rose off and put it all into wagos for the new fitting. The fitting wasn’t working (getting 25v) so I tried putting the pendant back but via the wagos as the new light is wired, this is where I’m getting 240v


The light has 4 screw bulb fittings for candle style bulbs (E14). I’ve checked the one I have installed and it has 240v

What kind of switch are you using? Simple mechanical or some sort of dimmer?

It is on a double dimmer switch that’s about 4 months old. The other side is the other (working) chandelier. If I’m getting 240v on the pendant can the dimmer be the culprit?

It’s this one from Screwfix. Not super impressed with it, has a bit of a lag coming on and adjustment is janky but I assumed it was working :confused:

I was going to declare that that’s your problem, but now I see that the chandelier has a conventional light bulb. Are you using the same light bulb in the original fitting as in the chandelier?

I have a random mechanical switch so I may give it a test.

Light bulbs: the pendant was a different bulb type but I’ve got 4 brand new ones which I’ve tried and I also took one from the working fixture and tried that. Not a bulb issue.

Wired the light fitting to some random flex and a plug. It works fine (lights up and had 240v at the bulb). So it’s something in the wiring or the dimmer. None the wiser as to what given it works with the other pendant I have

It was the switch. I swapped the side that is working on the other light fitting onto this fitting and now it works. So one side seems to be faulty. Will get a replacement. Thanks for the helpful nudges!