Can someone point me in the direction of my obvious error! I have taken a feed from an existing lighting circuit by cutting between light switch and light from a bedroom. I have taken the feed to a loft light switch. Neutral and earth are capped off, live is in Com on loft switch and L1 feeds the two baton fittings (which I split into a terminal block as opposite ends of loft). Bedroom light is off and loft lights work fine but when the loft lights are on, the bedroom light is very dim (although switched off). If I turn the bedroom light on, it turns the loft lights off? Should I be using L2 or am I missing something very obvious! Please advise
Are you a tradesperson and able to answer this question?
At a guess you have wired it wrong, you have wired it in series instead of in parallel. Suggest you call an electrician in as I’m not quite sure why you cut through the switch cable. You could have just taken the LN&E from the ceiling rose and into a j/b from there to the switch in the attic and to the lights and connected it all up from there.
You have installed your loft light using the live and switched live for your bedroom light switch so there is no neutral at the loft light. This means that the neutral path for your loft light is actually returning down your switch live cable to your bedroom; hence the dim light when the loft light is on. The loft light goes off because the bedroom light path to neutral has a lot less resistance so next to no amps flow through the loft light.
The loft light needs a permanent live, earth and neutral to be able to switch and operate correctly. I would advise finding an electrician if you are uncertain about installing a light fitting and switch. I hope this helps.
Sounds like you have "nicked a neutral" along with cutting into the switched live instead of a permanent live. It is quite tricky to get this right if your attempting a DIY job as you do need to have the correct terminations to make this work.
In an ideal world you should have 1x 1.5mm twin and earth coming from your from your 'permanent live + neutral + earth' in your bedroom main light to your loft switch. This will give you a permanent live "com" neutral and earth. You then would need to run an additional 1.5mm twin and earth from your loft light switch (live to L1. neutrals and earth connector blocked in the backbox correctly) out to your loft lights (live, neutral and earth) connections.
I would always highly recommend getting a fully qualified and competent electrician to carry out these works to ensure they are done properly instead of giving it a go yourself.
Hope this concludes your issue you have.
