Light fitting not working. Causes?

[AndySBD]

Hi,

I've got two lights on a 2 gang switch. One of which works fine, the other doesn't work at all.
It seems the switch is working correctly - power into one side, which it bridged to the other, and both switch lives are actually live when switched on.

In the dodgy fitting, I have 3 wires - 2 x single core neutrals which are connected together with a connector block, one side of which also has a small wire running to the neutral on the lamp holder, and one single core & earth live which goes straight into the lamp holder.

The neutrals, I'm presuming, are incoming from the previous fitting on the loop, and outgoing to the working light. (I did disconnect the connector block and the other fitting on the switch stopped working.)

The live in the light should be coming from the switch, yes? I've been up in the loft and traced the wiring, which seems correct.

The live in the lamp holder isn't live - sans juice at all. It's live at the switch end, but not at the light end. I'm not an electrician, I have a very basic grasp, so my initial thought is that there is something wrong with the switch live, like a break or something.

Could there be any other causes?

Any pointers would be gratefully received. Thank you.

 

[terryplumb]

What are you using to measure voltages present at the light fitting ?
Is there a junction box between the switch and the light fitting where the switch cable may be jointed ?

 

[AndySBD]

Hi, Thanks for your reply. I've used both a mains tester and a multimeter. Initially just a tester to see if there was anything there, then a multimeter. There isn't a junction box between the fitting and the switch, I can follow the leads in the loft where they come in and out of the ceiling.

 

[terryplumb]

What's the voltage at the switch ,switched live ?
If 240v it would appear there is a break in the cable between switch and fitting.

 

[Taylortwocities]

What's the voltage at the switch ,switched live ?
If 240v it would appear there is a break in the cable between switch and fitting.

There probably isn’t a neutral at the switch. Test between the earth and live and switched live.

 

[AndySBD]

I've got 240v at the switch. I swapped the switch wires just in case it was a faulty switch, but it wasn't. It looks like a break is the most likely. There's not an awful lot to go wrong. It's a tiny house with 5 lights in all. I'll have to find a way of pulling the cable out whilst being able to get another one in if there is a break. But I hear duct tape is your friend...

 

[oldbutnotdead]

Check the ends of the wires going into the not-working lamp (at both ends)- very common for cores to get nicked on stripping and eventually separate, usually just inside the insulation

 

[AndySBD]

Thanks for that. I'll check that out.