# Help please with wiring 12v switch



## michaelmorris (May 8, 2011)

I keep leaving the loo light on and it struck me that one way of reducing the number of times I do this is to replace the light switch to an illuminated switch. 

I bought an illuminated 12v replacement switch on EBay and took the old one off, expecting it to be a straight swap. In fact, the back is very different (see pictures). Has anyone any idea how I should wire up the new illuminated switch? 

The first picture is of the existing switch and the next two pictures are of the replacement switch. 

Thanks


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## cabby (May 14, 2005)

Cannot quite see the pics as they are very small, but assuming that there are 2 connections on both the switch and the light, feed to switch, wire from switch to light lastly return wire.
So really the same as your old one,existing cable to outer connections but link the switch and light using the inner connections so that turning off the switch disconnects the light.This should give you one cable/wire in each connection.

cabby


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## trek (May 1, 2005)

Looks as though the switch has 3 terminations so it couldl be a 2 way switch

So follow Cabby's advice but you may have to move a wire on the switch to try the other termination before it works 



Why not just move the two wires from the old switch to the new one and get the bathroom light working as required then when you know the switch terminations are correct alter wiring as per Cabby's advice to include the switch indicator lamp


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## Glandwr (Jun 12, 2006)

Pictures are too small. Might be an idea to post the ebay listing

Dick


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## Mrplodd (Mar 4, 2008)

Only ONE side of the supply to your toilet light is switched. Basically one side of the battery (usually - ) is connected to the metalwork of your vehicle (its reffered to as earth) The other side ( + ) goes to the feed side of the switch, and then onto the light when the switch is on! The wriggly amps then go THROUGH the light and back to "earth" The wriggly amps make the lamp glow !!! So if you have a tell tale on the switch that also needs to be connected to earth so that when the switch is on the wriggly amps can go through the tell tale and back to earth> Just think in terms of the tell tale being a second light controlled by the same switch.


Andy


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## cabby (May 14, 2005)

Have you stopped taking your meds Andy.>>>


cabby


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## dghr272 (Jun 14, 2012)

cabby said:


> Have you stopped taking your meds Andy.>>>
> 
> cabby


Nah, me thinks he's still on the wriggly capsules cabby. :wink2:


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## dghr272 (Jun 14, 2012)

Picture 1

The two wires going into the single terminal is the 12v + positive supply to your bathroom light and back out to supply something else.

The single wire with the white tape will be the switched + positive feed to light. The - negative for the light will be at the light fitting.

I suggest you follow Treks advice with trial and error to get the light working.

To get the indicator light working you need to connect a short jumper cable from the same terminal as the cable with the white tape is connected, + switched feed and one of the indicator light terminals, won't matter which one. But here your problems begin as the other indicator light terminal needs to be connected to a - negative source, without a negative the indicator won't light. 

As with all things electrical, if uncertain consult an expert to be safe.

Terry


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## Glandwr (Jun 12, 2006)

dghr272 said:


> Picture 1
> 
> The two wires going into the single terminal is the 12v + positive supply to your bathroom light and back out to supply something else.
> 
> ...


 Not forgetting that the indicator is probably a LED and polarised so will have to be connected the right way around.

I'm sure however if the OP looked at their purchases on Ebay and posted the listing that someone on here would be able to help.

Dick


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## erneboy (Feb 8, 2007)

If the light on the switch is in series with the light in the room no negative is required. A simple series circuit. I can't see that switch well enough to comment on it but there are plenty of 12v switches available which won't require a separate negative to light the light.

Not the right shape but this is one I think: http://www.ebay.co.uk/itm/12V-ON-OF...432?pt=LH_DefaultDomain_3&hash=item35ebbde538

Alan.


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## Pudsey_Bear (Sep 25, 2008)

Found a vid  

But this is more useful


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## dghr272 (Jun 14, 2012)

Kev,

OPs 3rd picture shows 3 terminals to the switch plus 2 terminals to the indicator light.


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## Pudsey_Bear (Sep 25, 2008)

dghr272 said:


> Kev,
> 
> OPs 3rd picture shows 3 terminals to the switch plus 2 terminals to the indicator light.


Yes, but if you look at the internal wiring in the posted dpic, it's clear what needs to be done, I couldn't find one that pictured his, the video does show the method though, perhaps if the OP is stumped someone local could pop round and sort it, shame he's not local to me.


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## Glandwr (Jun 12, 2006)

Kev that diagram would have the indicator neon on all the time:smile2:

Dick


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## Stanner (Aug 17, 2006)

What does having a small light in the switch do, that having a large light in the loo not do?

What am I missing?


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## Glandwr (Jun 12, 2006)

Stanner said:


> What does having a small light in the switch do, that having a large light in the loo not do?
> 
> What am I missing?


Presumably if it was wired correctly it would tell you that something (maybe out of sight) was on or off

Dick


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## Stanner (Aug 17, 2006)

Glandwr said:


> Presumably if it was wired correctly it would time you that something (maybe out of sight) was on or off
> 
> Dick


My switch is inside the toilet compartment where the lights are so the need for another light was lost on me.


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## cabby (May 14, 2005)

Well perhaps we should ask the OP as if the switch is so far away one cannot see if the light is on, again if it was an LED surely it would not matter too much.
Have to say that I found the pics too small to read them properly, did not notice how many connections. 

cabby


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## dghr272 (Jun 14, 2012)

cabby said:


> Well perhaps we should ask the OP as if the switch is so far away one cannot see if the light is on, again if it was an LED surely it would not matter too much.
> Have to say that I found the pics too small to read them properly, did not notice how many connections.
> 
> cabby


5 connection terminals cabby.


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## Pudsey_Bear (Sep 25, 2008)

Without seeing how it all connects inside it's a guess anyway, trial and error with a meter would be best, then wire according to results.


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## michaelmorris (May 8, 2011)

Thanks everyone for your suggestions, very helpful. I'll hopefully have time to give it a go at the weekend.



Stanner said:


> My switch is inside the toilet compartment where the lights are so the need for another light was lost on me.


Whilst there is a switch inside the loo, it's up on the ceiling and we tend to use the switch outside the loo in the main living area to turn the loo light on or off. The problem is that, so far, I've failed to remember to turn it off every single time I've used the loo. Having a light on the switch will hopefully prompt me to turn it off.


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## cabby (May 14, 2005)

Oh dear, that switch will not do, unless you wish to run an earth wire from the unit(switch).
Your existing switch has 2 wires on one terminal, this is a feed to the switch and a continued feed onwards to the next unit,the wire with the tape is the wire to the light, controlled by the switch.You will find that the lamp itself is earthed.
You could try a small proximity light in the bathroom instead, but if there too long will have to wave your hand occasionally.:wink2::wink2:

cabby


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## Glandwr (Jun 12, 2006)

michaelmorris said:


> Thanks everyone for your suggestions, very helpful. I'll hopefully have time to give it a go at the weekend.
> 
> Whilst there is a switch inside the loo, it's up on the ceiling and we tend to use the switch outside the loo in the main living area to turn the loo light on or off. The problem is that, so far, I've failed to remember to turn it off every single time I've used the loo. Having a light on the switch will hopefully prompt me to turn it off.


That means that is (or should be) a two way switch, can you get to the switch inside the loo? if so have a look how it is wired that will give you a clue.

Dick


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## cabby (May 14, 2005)

This thread is typical when an OP does not supply us with all relevant information, we spend so long in the dark we are unable to see a solution. Please take note all members please.

cabby


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## erneboy (Feb 8, 2007)

Why not just fit a red light above the existing switch on the feed to the bog light? Wired in series no earth needed?


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## Penquin (Oct 15, 2007)

erneboy said:


> Why not just fit a red light above the existing switch on the feed to the bog light? Wired in series no earth needed?


AFAIK if you wire a second light in series then the current that can pass is limited..... you may well find that there is insufficient to light up a series of bulbs as the small red light will limit the current that can pass.

The only way is to wire in parallel which requires a positive feed from the positive side of the switch and a negative connection - not via the same switch as that is NOT a negative wire but a "switched live"......

Dave


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## Pudsey_Bear (Sep 25, 2008)

Am I correct that the new switch will still be inside the loo, so still not visible, IE if you miss the loo lights, then a illuminated switch is going to do little to help, what I'd be inclined to do is add an LED lamp to existing loo lights, but the outside of the loo, if it's on then the loo lights are on, and it'd be easier to fix too.


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## cabby (May 14, 2005)

No he says they use the switch outside the loo, that is why he forgets. I think it's an age thing, as I do it at home on the odd occasion.:laugh::laugh:

cabby


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## Stanner (Aug 17, 2006)

First motorhome I've ever heard about that has a choice of switches for the loo light.


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## Pudsey_Bear (Sep 25, 2008)

cabby said:


> No he says they use the switch outside the loo, that is why he forgets. I think it's an age thing, as I do it at home on the odd occasion.:laugh::laugh:
> 
> cabby


Ah! thanks Philip, adding an external LED might still do the job though.


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