I want to install an extractor fan with timer in my bathroom. I want to operate it from an independent pull cord within the room. The light is switched on the outside of the room. I have a DP isolating switch (to be installed). The wiring diagram is for the fan to be operated from the lightswitch, so if it's possible for me to operate the fan from the pull cord then how do I go about wiring it all in? I've searched for this info on the site and can't quite get the info I need. Please help, damsel now getting stressed!!