The two groups of Blue / Brown & Earth will be power coming in from wherever it comes in from - the previous ceiling rose - and power going out to the next ceiling rose.
These groups should be joined blue with blue - brown with brown Earth with Earth.
The wires Red & Black will run to the light switch - look inside the switch and notice the colours - their Earth should join with the other Earths
Of these two - The Red wire carries power to the switch so it should join with the two Brown wires.
The Black will be the switched live return - ideally it should have a short Red or Brown sleeve on it to show that it's a live wire rather than a neutral.
The Black wire should have a terminal block of its own.
The light fitting will connect with the Black - Switched Live on one side - and with the Blue wires - Neutral - on the other.
It may help your understanding to make a simple sketch of the circuit so you can see what's going on - what should be going on.
Clearly the house has been re-wired - either that or an amateur has installed the cable to the switch - Red & Black are the old wiring colours and Brown & Blue the International IEC standard colours since 2004.
Take care as you work and remember Lord Finchley...
Lord Finchley tried to mend the electric light
Himself. It struck him dead: And serve him right!
It is the business of the wealthy man
To give employment to the artisan.
Good luck...
Joseph Swan
October 2014
howtomendit.com for free repair help, information and advice.
