Bathroom Light?

from what you say the loop is cable 1 and 2, so join these
together bare copper to bare copper ( earth ),
red to red ( live ),
black to black ( neutral ).
this should enable the rest of the lights to work
but NOT the bathroom light.
To connect the bathroom light you need to connect cable 3.
bare copper to the other bare copper (earth), also if
your light fitting has a earth wire (green/yellow)
connect this as well.
ONE of the reds to the other connected reds (live),
the brown wire of the light connects to the other red (switched live).
connect the blue from the light to the 2 connected black (neutral).
If in doubt call an electrician.

anon
August 2008