Bathroom light switch - can you fix it?

[securespark]

Well, first chek it's nothing simple like the lamp failed. try the existing lamp in another holder so you know it's working. Then try putting the reds and the brown together again in a switch terminal and see if the light comes on. If it does, great. If not, it could be the cable to the light fitting that's faulty or the lampholder itself.

So you could disconnect the wires feeding the lampholder and connect a temporary feed from a socket (via a plug) to the fitting to see if the fitting works or connect a temporary lampholder to the existing cable to see if that works.

Very long-winded, but without a multimeter.....

 

[333rocky333]

I think you need to go in loft and see if the brown and blue cable in the light is the other end off the brown and blue one in the switch position,

if it is then you have further problems as there is no earth to your metal light.

 

[securespark]

Can't go into the loft tonight -

Ah, sorry: missed that bit.

Yes, it might well make sense to do that first. Wait till morning, furtle around in the loft and have a butcher's to see what goes where.

In case anything is exposed up there, turn off the leccy before you go up.

Then you've got a better idea.

And Rocky's dead right, if tht fitting's not earthed, you gotta sort it one way or another.

Either rewire (if that's what you have to do) or connect up the cpc to the rest of the circuit.

Looking at the singles, it (the circuit) may well not have a cpc.

 

[securespark]

You need that multimeter more and more....

 

[diydiv]

Thanks again everyone for your very useful information. Phew, it seems I've got my work cut out with this one - and there I was thinking it would be oh-so-simple. I'll report back tomorrow to avoid any mishaps in the loft!

 

[diydiv]

I think you need to go in loft and see if the brown and blue cable in the light is the other end off the brown and blue one in the switch position,

if it is then you have further problems as there is no earth to your metal light.

If you refer back to the photo of the light, Rocky, it appears to be earthed, doesn't it? (the unsleeved wire just visible at the back of the fitting).

 

[securespark]

Well, it appears to be earthed in as much as the wire may be connected at the fitting end, but what if it is not connected at the other end?

I have visited quite a few properties over the years where extensions have been done and the lighting circuits have been wired back to the main building and attached to the nearest rose or point but because the original circuit had no cpc, that wire was left disconnected. Consequently, when I came to do an EFLI test in the extension, I was getting nothing.

This is what may be happening in your house. The double insulated singles hint that there may be no cpc (it's by no means a given), so the cpc attached to the bathroom fitting may be open circuit at the other end.

Having just looked at the piccy of the fitting, I'm hoping that T&E does not run to the PIR position, as there is no neutral, unless one of the DI singles is a neutral (which I doubt, otherwise the fuse/MCB would have failed when you put the wires together).

But then the light would not have worked at all, and if I remember rightly, you said it did, although it was erratic.

When it was working erratically, did it have an incandescent lamp in it by any chance? Have you changed that lamp since?

To go forward now, we have to see what you glean from going in the loft.

Take a paper and pen up so you can roughly sketch what wires go where.

Don't forget to switch everything off first.

 

[diydiv]

Thanks again, securespark. Yes, the light always used to work fine - until the last week or so when I found I had to tap it to get it to illuminate - so there is clearly a problem with the connection there. I'm not going to be able to go up to the loft till later this afternoon, so I'll keep you posted.

 

[securespark]

Crucial information which you seem to have omitted!!

It may be that the light will work with the red and brown wires connected together provided this mystery loose connection is dealt with.

Give it a go before you clamber in the loft.

 

[diydiv]

Hi securespark, so you mean the two red and brown should all go into common on the switch? I've been up in the loft and the situation is not great. One of the reds leading to the light is loose, but fortunately it's not live. But the loft floor is boarded up, so to get to the other wires, I'd need to shift loads of boxes and get the boards up - a job for the weekend perhaps.

T&E and single red in loft above light fitting

• diydiv
• 20 Jul 2012
• 1

Only one red leading to the light - not live. Does the T&E only go from here to the light...

The Loft - boards above wires to switch

• diydiv
• 20 Jul 2012
• 1

Wires at switch concealed beneath boards and heaps of accumulated junk - such is modern living...

 

[securespark]

Yup. As I've mentioned before, as a temporary measure, just put both single reds and the brown in one switch terminal so they are all together.

Then, if the lamp is working and the lampholder is sound and we have continuity, the lamp should light.

Then we can work out which of those wires goes in L1 and and which in C.

Obviously there are three wires. Unless it is a two-way (not impossible, but unlikely), then either there is another live feed tapped off the common or something else tapped off the switch side of the switch.

Have you got either a fan or other lights in the bathroom or a shaver socket, illuminated mirror etcetera, that worked either independently of or in tandem with that old PIR?

T&E and single red in loft above light fitting

• diydiv
• 20 Jul 2012
• 1

Only one red leading to the light - not live. Does the T&E only go from here to the light...

Is this the T&E that appears at the fitting or the PIR?

And the single: is that chopped off? I can't quite tell.

You can't see where it goes 'cos the loft is boarded.......

Don't want you to take risks but it would be interesting to know if it was live....

 

[diydiv]

Uhuh, that the T&E that appears at the fitting. The single is chopped off, but it doesn't read as live with the pen tester.

 

[securespark]

And I guess you can't see where it goes?

The thot plickens....

 

[bernardgreen]

Uhuh, that the T&E that appears at the fitting. The single is chopped off, but it doesn't read as live with the pen tester.

Is that "pen tester" a screw driver with a neon in it. If so throw it in the bin....

If it lights up it means there is a difference in potential greater than ( approx ) 180 volts between the hand holding it and the item it is touching. The item may be earthed or neutral but the lamp may glow if your body is more live than grounded due to either [1] direct contact ( very dangerous ) with a live item or [2] capacitive coupling to ( not uncommon ) to something that is live ( intentionally live or live due to a fault ).

The worst thing is they may not light when touching a live item because your body is not providing an adequate path to ground for the neon to light. You think the item is dead, you work on it and the chances are you will soon be dead or injured.

 

[securespark]

I've borrowed an electric pen tester from a friend which glows red when a live feed is detected.

Methinks it's a volt stick, but I'd like the OP to confirm it's non-contact please!