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DIY here. Not a novice, but far from an expert…

I’m replacing a ceiling fan, as well as adding a second switch to separate the fan controls from the light controls. I have 14/2 carrying power into the ceiling box. Then I have 14/3 leaving the ceiling box and going into the switch box (now switches). I also have 14/2 leaving the switch box to a receptacle in another room. I’m a little perplexed on how to wire the fan/light as well as how to make connections in the junction box. I thought I read that code required all neutrals to be tied together in the switch box, but I can’t find the citation anywhere. Do I just tie the whites together at the ceiling box and then tie the whites together again at the switch box?

I feel like I’m trying to make this more complicated than it should be. Anyone have a diagram and/or instructions to steer me in the right direction?

PS, this is a 15A circuit, all wires have grounds, the switches are not smart switches, and my local code is NEC 2017

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  • Are you OK with adding a full-blown fan control with a module at the fan?
    – ThreePhaseEel
    Commented Aug 2, 2022 at 1:25
  • Not sure what you mean @threephaseEel
    – Rudy
    Commented Aug 2, 2022 at 1:56
  • I.e. something like a Lutron Maestro that provides fan speed control and dimming
    – ThreePhaseEel
    Commented Aug 2, 2022 at 2:00
  • Probably not. I actually already have the two gang box in the room. Long story short, I’m removing a wired nightlight and replacing it with the separate switch. I’d rather rewire the whole house than repair sheet rock!!!
    – Rudy
    Commented Aug 2, 2022 at 5:35

2 Answers 2

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You can't do this with the existing wires. I'm assuming that you presently have one switch and the receptacle in the other room. In this case, the 14/3 is presently carrying hot, neutral and switched hot. The hot and neutral are carrying on to the receptacle. The switch connects hot to switched hot which goes back to the fan.

To add the second switch, you need a second switched hot for the light. If you repurpose the neutral as switched hot#2, you no longer have a neutral for the receptacle. (You are also breaking code which requires a neutral in the switch box.)

To make this work, you'll need to replace the 14/3 with 14/4 and no, you cannot just run an extra wire. Everything has to be in one cable. Actually, you could add an additional 14/2 from the fan box to the switch box, carrying hot and switched hot#2 for the light switch.

You might be able to make it work with smart switches, but I'm not sure how.

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  • Thanks for the reply. I was afraid that was the issue. So, if I take your suggestion to add another 14/2, does the white essentially become the switched hot? And I don’t need a neutral for that?
    – Rudy
    Commented Aug 1, 2022 at 5:43
  • @Rudy That’s basically correct. I believe that code actually specifies to use the black wire as switched hot and the white wire (color the ends black with paint or tape) is hot.
    – DoxyLover
    Commented Aug 1, 2022 at 6:28
  • 2
    No that doesn't work @Rudy... you can't use a 14/2 like that (taped white as always-hot) because that violates NEC 404.2(C) requiring a neutral in the light switch cable. "But neutral is in the 14/3 cable" nope, that's a 300.3 violation. Best you can do with that layout is use the new 14/2 to have supply hot/neutral bypass the fan box and go straight to the swtich box... and then wire the fan+light conventionally (non-switch-loop) on the /3.
    – Harper - Reinstate Monica
    Commented Aug 1, 2022 at 20:59
  • Thanks, Harper. Question though. Could I add a 14/3 cable (instead of a 14/2)? That way, each of the 14/3s (existing and new) allow for a switched loop as well as a neutral at the switch?
    – Rudy
    Commented Aug 1, 2022 at 21:30
  • Actually @harper, I just re-read your post, so ignore this comment.
    – Rudy
    Commented Aug 2, 2022 at 1:59
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You have two problems:

  • You are trying to tap additional power off a switch, which classically does/did not work. Because switches don't have power at them, since neutral is part of "power". Well, switches did not pre-2011.

  • The above problem wouldn't be a problem post-2011 when neutrals on switch loops became required. However your installation only has a /3 cable, forcing you to choose between a) having neutral on the switch loop OR b) having separate control of fan and light, which then forecloses any possibility of extending the circuit beyond the switch loop.

So if you use black for always-hot, and white for neutral, you only have red left over to control both fan and light. That only works if they switch together.

It sounds like you found it this way, and are now hoping to split control of fan and light without adding any wires. Well if it was possible with the wires in the wall, the last guy would have done that. Everyone likes separate control!

Option 1: automatic

Since always-hot and neutral are available at the fan box, maybe it's time for an automatic fan or a motion sensor light. Now you only need to switch 1 thing, and you have the wires for that.

Option 2: Replace /3 with /4 cable.

Better stores (read: NOT Home Depot or Lowes) will sell /4 or /2/2 cable by-the-foot. Now you have all the wires you need.

Option 3: Add a /2 cable to the /3.

This is tricky, because it flips the /3 cable from being a "switch loop" into being conventional "power at the switch" control of fan+light. The supply bypasses the fan altogether.

Supply hot+neutral comes into the fan box, and is immediately spliced to the new /2 cable and nothing else. Thus it is not tied to the fan in any way (except safety ground).

The new /2 cable enters the switch box as a power line. It splices into the onward /2 cable to other loads, and then, is wired as a conventional switch.

The /3 cable is flipped to be conventional - white is fan+light neutral...... black is fan, and red is light (or other way round, doesn't matter).

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  • So, if I’m understanding you @harper, the existing 14/2 (carrying the hot) can be connected to a new 14/2 at the fan box (FYI, I plan to put a new junction box near the existing fan box for that…not much room in the pancake box). The new 14/2 will carry the hot into the switch box, where I can join it with the 14/2 that is leaving the switch box as well as jumper it to the two switches. Then the existing 14/3 red/black carry switched power back to the light/fan. Neutrals connected and grounds connected at all 3 locations (fan/light box, new j-box, switch box). Does that sound about right?
    – Rudy
    Commented Aug 2, 2022 at 2:11
  • @Rudy both supply hot and neutral must go down the new cable. That means supply neutral will pass right through the fan without being used by the fan! This is important! Neutral has to come back up the /3 cable. NEC 300.3. If you don't understand why, you are thinking in DC power.
    – Harper - Reinstate Monica
    Commented Aug 2, 2022 at 18:23
  • @Harper-I think I’m on the same page as you now. So I will be all right as long as I am connecting the new 14/2’s neutral (white) to the existing 14/3’s white at the switch and then connect the other end of the existing 14/3’s white to the white of the fan/light, correct?
    – Rudy
    Commented Aug 2, 2022 at 18:41

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