So I've been replacing most of the switches at home to smart switches and ran into one I can't figure out.

It's wired like this:

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Here's a pic of the switch (Circled in drawing)

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Can I even put a smartswitch here? There is a ground wire, but it's grounded to the box the switch is in. When I disconnect the switch, I have no power to either outlet and obviously the light and ceiling fan. TIA!

  • Is one of the outlets switched with the ceiling fan/light? Are there only these two terminal screws on the switch, or is there a third on the opposite side (I think after looking closely it's just one of the wires being in a clamp hole rather than on the screw, but my first thought was it was a 3-way switch.) Removing the switch (without joining the wires) will of course cut off power to everything fed from the power to it. A quick wirenut of two wires at a time will sort out which wire is which, by what gets powered, normally. – Ecnerwal May 9 '19 at 14:49
  • Other side of the switch has an unused ground screw. The outlets don't lose power when the switch it turned off, just the fan and light. – Francisco May 9 '19 at 15:02
  • Then I suspect your diagram is not quite right, or else there's a wirenut with additional blacks connected to one of the lower right blacks out of sight. You only have 4 wires here, and your diagram indicates 1 in and 4 out (with the fan and light being the red and black on the switched side, since neither outlet is switched.) – Ecnerwal May 9 '19 at 15:09
  • Sorry, there is a white wire in the box connected via wire nut. – Francisco May 9 '19 at 15:12
  • No need to be sorry, just trying to figure out what's really going on here. – Ecnerwal May 9 '19 at 15:25

The 2 blacks at the bottom will be the live from the breaker and the live to the outlets. There will be another place where the wire continues to the other outlet.

The red and black are going to the fan/light. The reason for 2 wires being switched is to allow easy upgrade from single switch to a combo switch that controls the light and fan separately.

The whites are the neutral.

So the smart switch will take line in from the bottom black which will need to be wirenutted and pigtailed if the switch doesn't allow 2 wires per connection. The neutral will be an addition white in the bundle of neutrals. And the switched out will be the red/black combo (again wirenut as needed).

  • Thanks, I'll try this! – Francisco May 9 '19 at 16:49
  • 1
    ...and you should probably pigtail a ground wire from the switch to the grounding screw on the box. – Ecnerwal May 9 '19 at 18:12

The red and the black are almost certainly both switch legs going to the fan box. The idea is to have the ability to control them from separate switches. If one of the outlets is switched, we need to know that.

The two wires on the right side of the picture are on the hot side of the switch, and the switch is being used as a wire connector. Wire nut those two together with a third pigtail wire, use the pigtail to connect to the hot side of your smart switch, and you should be good to go.

Are there more wires stuffed inside that junction box? According to your diagram, you have four neutrals and 4-5 hots in it.

  • The outlets are not switched, they stay on even if the switch is on or not. There are white wires connected via a wire nut in the box yes. – Francisco May 9 '19 at 15:07

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