I have fitted four downlights in a ceiling void. The existing wiring included an extractor fan. I isolated the mains supply and removed the the wiring from the original junction box which fed the fan and one central light. I rewired the new lighting circuit using the original live feed and the lights did not work. The voltage on the live feed registers 25 volts. The light and extractor worked previously. What has happened?
25v is almost like an induced voltage one sees on the neutral sometimes, I would hazard a guess that you have got the wiring mixed up, obviously, 'cos it don't work. Any chance of a piccy or two of the wiring?.