UK Swap out Extractor Fan

[Segandy]

Hi all.
I’m looking to swap my old noisy bathroom extractor fan for a new one and am after some advice on the wiring.
My old one is on a timer and comes on with the light, turns off after around 2 mins.
The new one doesn’t have a timer (it’s next to a bedroom and just a toilet).
The wiring is a Red, Black, Yellow & an Earth(not used), the old fan has 3 terminals for these to wire into.
The new fan has just 2 terminals.
Im guessing one of the wires is a switched live? And if so, how do I wire it into the new fan so it comes on & off with the light switch?
Thanks in advance
Andy

 

[brianmoooore]

Sure it's red, black and yellow? All in one cable?

 

[Segandy]

Sure it's red, black and yellow? All in one cable?

Apologies.
red BLUE & yellow!

 

[telectrix]

isolate at Fuse box first. blue into N. the switched L willl be red or yellow (probably yellow) into L. terminate red into a choc block or wago on it's own. if that's right, when re-energised, it will work with light. if it comes on all the time, swap red and yellow.

 

[Segandy]

isolate at Fuse box first. blue into N. the switched L willl be red or yellow (probably yellow) into L. terminate red into a choc block or wago on it's own. if that's right, when re-energised, it will work with light. if it comes on all the time, swap red and yellow.

Perfect!
cheers