Here's the problem:

I have three underhouse rooms for storage all three have lighting (flourescent) switched from within the rooms.They are on two separate circuits.

Several times me or my girlfriend ( ) have forgotten to switch off the lights in one of the rooms and have not discovered this until the next time we went to the room.- maybe a week later .

I want to install an external warning light (one is enough in principle).

Here is the question:

Can I join the 3 switched lives in a junction box and then take one wire to the lamp and then since they come from two different circuits what about the neutrals?

If I can't do this any electrical suggestions.

Thanks in advance

Put each on a timer either one that replaces the switch (mechanical timer) or even motion detector style.

Sure Crossy will be along in a moment with a proper answer, but possibly if you connect the three feeds to one warning lamp all three lights will come on every time you switch on just one.

Or why not just wire in an external LED bulb, like a 4 watt, would be cheap and effective.

Thanks Daffy,

Hopefully Crossy will be along.

And what you say is exactly what I want - if any light is on I want the warning light to come on.

Or why not just wire in an external LED bulb, like a 4 watt, would be cheap and effective.

Does seem like the simplest solution but you would need two Lamps.

They are on two separate circuits

I agree with daffy, simply break into the feed from the switch to any of the lights, with new junction box and fix an external fuorescent or small bulb in a position you can see it.

Same switch operates all the lights..

Don't forget to switch off power on your fuseboard before tampering.

You can't join the switched lives to a single lamp, you'll back feed the other lights so, as noted above, turning any light on will turn all three on

You could get those illuminated switches with a neon / LED across the contacts, light on = switch off.

A small plastic box with 3 neon indicators lights in it mounted somewhere visible would also do the trick, common one side of the neons to a convenient neutral and run the other side to each switched live.

Actually Crossy if it's not electrically dangerous that wouldn't be a problem since all the lights would be only for max 30 mins which is far less expensive than one set being on for more than a week!

I think one switch feeding all the rooms is fine. I think Crossy is concerned about multiple switches.

Actually Crossy if it's not electrically dangerous that wouldn't be a problem since all the lights would be only for max 30 mins which is far less expensive than one set being on for more than a week!

I would avoid retaining the three switches and use a single switch for all lights..

No hazard whatever using a single switch and a nice obvious indicator lamp.

Sometimes I fall asleep watching TV. Can I hook up a warning light on the live to the TV and then route over to my bed or should I just get a new wife?

PIR or movement detector, that switches off when there is no movement. Have them installed in my kitchen, and bathroom cos wifey is always leaving them on! They switch after 5 mins of non activity.

Just connect the cables at the switch (optional), and put the detectors just in front of the lights!

http://www.cpelectronics.co.uk/energy-saving-products/presence-detectors-pir-sensors-and-microwave-sensors

Have seen them here (got mine from UK) If not ebay singapore is your friend

PIR or movement detector, that switches off when there is no movement. Have them installed in my kitchen, and bathroom cos wifey is always leaving them on! They switch after 5 mins of non activity.

Just connect the cables at the switch (optional), and put the detectors just in front of the lights!

http://www.cpelectronics.co.uk/energy-saving-products/presence-detectors-pir-sensors-and-microwave-sensors

Have seen them here (got mine from UK) If not ebay singapore is your friend

Off topic (but related).

Some years ago the company I was working for in the UK installed PIRs in the toilets in order to save energy. Unfortunately the time-out was just a little shorter than the time required for a really good dump.

One dark winters morning the lady cleaner was put in shock by the sight of a young engineer with his trousers round his ankles franticly waving to get the bog lights back on.

The units were removed.

The young engineer was me (so you can see it was a really long time ago).

Unfortunately the time-out was just a little shorter than the time required for a really good dump.

Hope with practice over the years you have managed to reduce your dump time

Actually modern ones work on microwave technology, which means body heat, but are more expensive.

Not required for this instance.

Sent from my SM-G900F using Thaivisa Connect Thailand mobile app

This is my soloution for my attic light.

But that soloution only works is if your switching point is in the living area and not near the storage area.

Simply just pick up the switching wire and run a short loop into the back of the neon indicator and pick up

a neutral from anywhere at the back of the switch.

Alternatively, something like this?