Wiring a bathroom shaver/light socket.

[Mr_Hat]

Hi all,

I had what I thought to be a faulty shaver/light socket in the bathroom, so I replaced the unit, wiring it in exactly the same way as the old one...and the new one doesn't work either...so I suspect that wiring is to blame.
There are 4 wires, 1xBlue 1xRed 1xBare (Which I assumed to be earth, so I put some green/yellow earthing sleeve on it, and 1xYellow.
Both the Earth and the Yellow were disconnected from the original unit (old unit was plastic, new one contains some metal)

Any ideas what this yellow wire is for, and is it ok to remain disconnected?

Many thanks in advance for your help.

Photo of new unit here:

 

[ban-all-sheds]

Hi all,

I had what I thought to be a faulty shaver/light socket in the bathroom, so I replaced the unit, wiring it in exactly the same way as the old one...and the new one doesn't work either...so I suspect that wiring is to blame.

How do you know that the old one was correctly wired?

Wouldn't following the instructions for the new one have been a better idea?

Any ideas what this yellow wire is for, and is it ok to remain disconnected?

No idea - why not use your multimeter to find out if it's live some or all of the time?