Hi greeny181 Six months after you posted your wiring drawing for the bathroom fan I just want to thank you for your help. This was the most useful and easiest to follow drawing I have ever found on the net. Thanks again.
I used Greeny181's wiring layout to wire my extraction fan, but I also wanted to add a ceiling mounted PIR switch to the bathroom. I used a Timeguard SLFM360L PIR, a Manrose MF100T in-line fan, a Screwfix 69862 fan isolator switch, and four Aurora AU-FRL801 LED downlighters. The PIR switch has a handy manual override function so that you can keep the lights on permanently. The manual override is provided by a double on-off switching action to the PIR power supply, so to achieve this I located the switched FCU on the wall outside the bathroom. I've rejigged Greeny181's wiring diagram to show the circuit. I hope it uploads OK. I hope you find the info useful, but I'm not a qualified electrician, so use the circuit at your own risk. Once again, thanks to Greeny181 for original wiring diagram.