Light switch - Wrongly Wired?

[fozzy9876]

Hi, hoping someone can help...

Last year I changed a light switch for a dimmer in Bedroom 1. I thought I had wired the dimmer in the same way as the previous switch but now im thinking I got it wrong.

In bedroom 2 the light went, I changed the bulb and then the switch but it still wouldn't work. Now last night in Bedroom 1 the light went pop. I tried changing the bulb but that I think blew without ever turning on (its making that ratling noise of broken fliament).

The wiring in room 1 has 3 red wires, so im thinking I might have confused one of these when rewiring the dimmer. This might be causing the problem in both rooms.

I have one of those voltage pens but dont know what to be checking for. I have looked at the help threads but the 3 red wires is confusing me!

Mark

Bed room 2

• fozzy9876
• 9 Mar 2013
• 1

Bed room 1

• fozzy9876
• 9 Mar 2013
• 1

 

[Iggifer]

do those two wires into the dimmer have a mark on them?

The third cable, that isn't connected, did you cut off the stripped copper or was it always like this?

When you swapped it for the dimmer were there two or three cables into the switch?

Does the room with the dimmer have more than one light fitting?

 

[fozzy9876]

do those two wires into the dimmer have a mark on them?

The third cable, that isn't connected, did you cut off the stripped copper or was it always like this?

When you swapped it for the dimmer were there two or three cables into the switch?

Does the room with the dimmer have more than one light fitting?

Hi,

No marks really, one looks like it might have had tape on at some point but can't tell the colour.

I cut the copper on that one.

Think there might have been one wire lose but I reallly can't remember.

There is only one light in each room.,

Thanks

 

[PrenticeBoyofDerry]

Do you have an proper means of testing for continuity and voltage?
The voltage stick/pen are not that reliable!

 

[fozzy9876]

No just the pen unfortunately.

 

[PrenticeBoyofDerry]

No just the pen unfortunately.

You need to get a multi-meter then.

 

[fozzy9876]

Ah ok thanks for your help. If I had a meter would it be fairly easy to work out the problem?

 

[securespark]

Easier than a pen!! And only a tenner from Maplin.

Do any of the rooms have more than one switch for the light?

 

[fozzy9876]

There is only one switch per room. Will try to pick up a meter tomorrow as sounds like I'm going to need one. Thanks for your help guys.

 

[xr4x4]

It might just me, but I can't see any neutrals..?

 

[Spark123]

My 10 is on the dimmer switches have gone pop, or you are fitting dead lamps.

 

[phatboy]

It might just me, but I can't see any neutrals..?

Maybe the property is wired in singles, so there are just the reds?

 

[fozzy9876]

Ok I have a multimeter and understand basics I think (mains off, testing, ohms minimum resistance) I think I need to

1) check my new light switch actually works!
2) find the switch live, label and connect everything up correctly

Had a look at the wiki, etc, but not sure the easiest way to test for switched live from my 3 red wires?

Do I need to connect them to the switch to find switched live. i.e. when I have two connected with switch 'on' there will be continuity with a low voltage. Then switched to 'off' it will result in high resistance?

 

[fozzy9876]

Fixed now and both bedroom lights are working.

The multimeter confirmed the dimmer had blown.

With mains on I found the live wire using the voltage reader on the multimeter. I then tried connecting it to the other two to find the switch wire (light will come on).

With mains off I rewired everything on the new light switch I had bought. I connected the switch wire to L1 and both the live in (and presumably live out) to Com. All is working fine.

Hope this helps somebody else and cheers to those who replied to my questions.

Just to mention, my way of finding the switch wire may not be the recommended (safest) way of doing it!!!

 

[securespark]

Just to mention, my way of finding the switch wire may not be the recommended (safest) way of doing it!!!

My introduction to fault finding (by my boss!) as an apprentice was to fiddle about at switches by shorting live wires together to see what happened...

Them were the days...