My bathroom has a light, an exaust fan, and two switches. Someone before me rewired it so one switch controls the lights and fan together, the other does nothing.

I know how to switch it back to one switch each, but what I really want to do is set it up so:

  • Switch A turns on the light and fan.
  • Switch B just turns on the fan.

That way we could leave the exaust fan running when needed without having to leave the lights on, but nobody could forget to turn it in when they take a shower (unless they shower in the dark).

Is there some way I can wire it to do that?

  • Can you post a photo of the inside of the box? It sounds like what you want is possible, but I'm not sure how much room you have to work. Also, what are the nameplate ratings on the fan/fan motor? (HP, amperage) Commented Aug 29, 2016 at 11:43
  • What about controlling the fan with a humidity sensor, so the fan turns on in response to the humidity level of the bathroom.
    – Tester101
    Commented Aug 29, 2016 at 14:21
  • @threephaseeel not there to take a pic right now. Its a typical two switch box, not sure how deep it is though. Can't get at the fan nameplate without going in the attic, but its a small cheap loud bathroom fan. Nothing fancy.
    – Grant
    Commented Aug 29, 2016 at 21:28
  • @tester101 that is a good backup option. Humidity isn't the only reason I don't want people to forget to turn on the fan in the bathroom though.
    – Grant
    Commented Aug 29, 2016 at 21:29
  • @Grant they make Poo-Pourri for that.
    – Tester101
    Commented Aug 29, 2016 at 22:03

1 Answer 1

  • this eliminates the need for a relay by isolating the fan circuit from the light
    – joe
    Commented Aug 29, 2016 at 14:32

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