UK Bathroom Fan wiring to ceiling rose with old line and neutral

[Waseem]

Hi, have an old bathroom fan. Which has two wires the black and red (line and neutral).
The fan has no isolator switch and was powered when the bathroom light came on. When turning the light off, the bathroom fan stopped.
I disconnected the fan wiring from the ceiling rose to clean the fan. Now not sure where the line and neutral wires go. I’m guessing the line would go the L in the ceiling rose and neutral to N terminal in the ceiling rose. So it works when the bathroom light comes on and works when it goes off. Any second opinion on this would be great?
Also if I was to get a new fan, with L,N and SL terminals. Yet unable to change the cable to a three core and earth. How would the wiring be in the ceiling rose for twin and earth (already embedded within the ceiling)?

 

[Chivers]

Have you a pic of the Ceiling rose? If you do what you say it sounds like the Fan would be permanently On

 

[Waseem]

Have you a pic of the Ceiling rose? If you do what you say it sounds like the Fan would be permanently On

Sorry Chivers, don’t have a picture of the ceiling rose currently. Ceiling rose just has a power supply coming in from the next door room. Then a bathroom cord from the same ceiling rose. The fan was connected to the ceiling rose. Just want the fan to come on when the bathroom light comes on. Want the bathroom fan to turn off when the bathroom light goes off. No timer function on the fan.

 

[westward10]

It would normally be the outer terminals where the flex of the pendant drop connect.