
Russell Baron
Hi Amy I take it we are taking an upstairs bathroom. Basically you will have a 3core and earth cable between your light and fan via the isolation switch. You will have a switch feed which triggers the fan when the light comes on and a perm live which allows the fan to run on for a set amount of time after turning off the light. The wiring should be easy to access and test and both the light and fan units within the bathroom.Should be an easy fix Hope this helps If your in Lancashire you can find me on Facebook Russ