Live cable in 2 gang light switch going nowhere

[LeighSawczyn]

A customer wants the light switches changed from white plastic to brushed nickel and has already made a start. Needless to say the 2 way switching needs sorting as they don't work as they should. By the front door there is a single gang switch for the outside light, then about 6 inches along there is a 2 gang switch. One of the gangs is for the hall light the other??? Goodness knows. The feed is still live, the switch is faulty so the cable is live all along its route to wherever it terminates. Any suggestions on why there is a switch with a live feed which doesn't operate any light to the best of the customer's knowledge. They want me to investigate as they are concerned about it. Funny thing is upstairs on the landing there is also a 2 gang 2 way switch with one of the switches live but again controls nothing. The property is only about 15 years old and doesn't seem to be subject to DIY electrics. How would you go about finding where the live wire leads to?
Thanks in advance.

 

[trev]

Time for some continuity testing maybe?
Perhaps this live at both switches is one and the same?
It's getting a feed from somewhere mate, it shouldn't be too big a job to find out where from.
Isolate the circuit, is it still live? If yes, keep isolating. If not start belling out individual cables on that circuit. You'll soon track it down

 

[PEG]

Hi dude,the "customer already making a start" would make my investigation move to defcon 3...You will have to start your testing from what you know and can see,if the two switches are diverting a live somewhere,then you need to find where.Leaving these as they are,with neither the customer or yourself knowing where they terminate,would not sit well with me. Some of these later build properties have some snidey wiring routes and methods,age and NHBC mean nowt.Trace them and identify their route and purpose,and you will be best part there.

 

[PEG]

Time for some continuity testing maybe?
Perhaps this live at both switches is one and the same?
It's getting a feed from somewhere mate, it shouldn't be too big a job to find out where from.
Isolate the circuit, is it still live? If yes, keep isolating. If not start belling out individual cables on that circuit. You'll soon track it down

I thought for once i'd get a second post....beaten by a pro...

 

[HappyHippyDad]

I'd like to get my teeth into that one!!

Is it T&E going into the redundant gang of the 2g switch or 3 core? Is there a neutral in either of the 2 gang switches (would be handy if it was just being fed from the other gang!)

Perhaps a 2 way switch for the upstairs light, especially as the upstairs one is the same?

If it's really not doing anything after you've investigated a bit (would be nice if it's a 2 way for the upstairs and you get it working!) you've just got to find out where its being fed from and disconnect/make safe and hope its not a junction box under the floorboards somewhere!

 

[LeighSawczyn]

No neutral and 3 core

 

[Rockingit]

Leigh - until you've done the basic tests as per Trev's post ^^ then you're shooting in the breeze. It could be anything from a 2 way that never got finished through to something less obvious. And never ever take a customers word!

If it becomes a pain and you need a hand, I'm local, just ask.

 

[HappyHippyDad]

No neutral and 3 core

Well I'd probably be thinking 2 way for the upstairs light then. Hopefully the upstairs also has 3 core and a T&E going into the gang that is in question, otherwise it may well be a JB feeding it. Do you know whats going into the upstairs gang that is in question? Like Trev said time for some continuity testing.

 

[jaypp]

A customer wants the light switches changed from white plastic to brushed nickel and has already made a start. Needless to say the 2 way switching needs sorting as they don't work as they should. By the front door there is a single gang switch for the outside light, then about 6 inches along there is a 2 gang switch. One of the gangs is for the hall light the other??? Goodness knows. The feed is still live, the switch is faulty so the cable is live all along its route to wherever it terminates. Any suggestions on why there is a switch with a live feed which doesn't operate any light to the best of the customer's knowledge. They want me to investigate as they are concerned about it. Funny thing is upstairs on the landing there is also a 2 gang 2 way switch with one of the switches live but again controls nothing. The property is only about 15 years old and doesn't seem to be subject to DIY electrics. How would you go about finding where the live wire leads to?
Thanks in advance.

Gut feeling is customer had a go as 'it's only a few wires', mixed up those few wires and thought 'better call a spark'. Bet he didn't earth them either. If no evidence of works, has he got old plates to check they were 2G too!

 

[BlueToBits]

Hall AND landing 2 way switching?

 

[LeighSawczyn]

Spot on BlueToBits! I went there today and did a continuity test between the 2w switch in the hall and the 2w switch on the landing. Obviously someone at some point had added another 2 way circuit in the hall to the landing rendering this one obsolete. It's always nice to get to the bottom of a problem, helps me to sleep better at night. Thanks everyone for your input. Case closed!

 

[LeighSawczyn]

Unless they just wired it up wrong when they put the new switch on. They said the switch had never worked anyhow so they won't miss what they never had!

 

[trev]

Hall AND landing 2 way switching?

Yeah, it's pretty common. The house I grew up in had it.

 

[Clive P]

Hi,
Had one a while ago, mix up with 1 Way and 2 way switch wiring ( DIY disaster ). Never worked I was told, and two other Electricians had looked at it. Got the long lead out, identified all the cores and Bob's your uncle.

Regards.

 

[davesparks]

Or if you don't posses a long lead the good old fashioned method is to use the one that someone has kindly left there for you, the CPC!