Hi, I have been waiting for my landlord to change my bathroom extractor fan over (installed in 1994!) as it makes a horrible screeching noise when its cold, so I've managed to source a replacement (its an Greenbrook G510, formerly RDL G510) and although I don't do that much DIY, I have dome some simple stuff, and didn't think a fan like this would me much trouble, however, after taking the cover off, I was completely taken aback by all the wiring (photo below) - the fan itself has only has 2 connections (L & N according to the schematic I downloaded) but I can't really tell whats happening here - can anyone help me out please? From what I can tell, its just a simple Light ON - Fan ON, Light OFF - Fan OFF set-up ...