Black Series Dimmer - No Neutral 3 Way Wiring

Hi All!

I just installed a Black Series Dimmer and a GE Add-On Switch for a three way light. I also installed an Aeotec bypass at the fixture since it’s low wattage.

The dimmer is working, but the add on switch isn’t - I think I’ve got it working just as an expensive wire nut at this point.

I’m attaching pictures of the wiring set up with the original 3 way switches (1950s house): Album

Switch A has 3 wires in the box - white, black, and a wire wrapped in red electrical tape.

Switch B had three wires connected to it - also red, white, and black. However the black wire going to the switch is coming from another romex line coming into the box and the black from the romex shared by the white and red goes to another switch in the box.

I haven’t been able to find any wiring diagrams or descriptions that describe this setup, so I’m hoping someone can help me sort it out.

I also tested the wiring with a multimeter:

  • Switch A Up - Switch B Red & Black = 120 V
  • Switch A Down - Switch B Black & White = 120 V
  • Switch B Up - Switch A Red & Black = 120 V
  • Switch B Down - Switch A Black & White = 120 V

I feel like I’m missing something simple, hoping you all can help!

Edit: I did program the Inovelli switch for the Add-On setup also.

You should only have two wires connected to the aux switch. We’ll need to figure out your setup. Got a multimeter handy?


Yep - I thought that was the case! But what do I do with the third wire :upside_down_face:

See OP for what I got testing wires

We need to find hot. Coming into switch a or b box?

Third wire will either be capped. We just need to find out if it’s line/load same box or different box. Different box option may not work. Need to draw it out.

Were ALL THREE conductors attached to each of the dumb switches all from the same 3-wire Romex? That looks to be the case but you need to confirm. In other words, there was NOT also a 2-wire Romex with at least one conductor connected to the switch in one of the boxes.

@harjms Not sure that’s the correct diagram. Depending on what the OP says, I’m thinking power to the light in the middle, non-neutral.


@Bry probably right, but just needed some meter checks to confirm setup.

Here’s a better picture of the wiring at Switch B

The white and red from one romex were attached to the original dumb switch. Black from the same romex is attached with a wire nut to the white from a second romex. The black from the second romex is attached to the original dumb switch.

Which wires do I need to check with the meter?

Ok, thx. So it’s not what I was suggesting. Back to @harjms

OP, we need a better pic of the box. Please get down lower so there isn’t a shadow inside the box. We can’t see where the black conductors originate from.

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Broke out the spotlight, hope this is clearer!

So looks like to me, power comes into this switch box via WHT of the 2 romex, then jumps over to the other switch box via the BLK of the 3 wire romex to the “COM” of the switch. Then the travelers of the 3 wire romex do their thing…The “COM” of this switch box then goes back to the light via the BLK of the 2 wire romex.

With your meter, confirm you have line voltage on the WHT of the 2 wire romex (with it untwisted from the BLK) to ground.


There is line voltage on the WHT of the 2 wire romex when it is untwisted.

Are you set with the Inovelli in Switch Box A or can it go in this box?

Ideally I’d like to keep it in box A (in the room) vs. this box (in the garage), but if it’s significantly more difficult, I can adapt!

This is what I’m thinking: @Bry can verify.

Switch box A:
Connect BLK to Inovelli Line
Connect WHT to Inovelli Load
Connect RED to Inovelli Traveler

Switch box B:
Connect a pigtail from the WHT/BLK bundle that contains LINE to Neutral of Aux Switch
Connect WHT from 3 wire romex (Load from Inovelli) to the BLK of the 2 wire romex
Connect RED from 3 wire romex (Traveler from Inovelli) to Traveler of Aux Switch.

I think that’s correct.

Didn’t draw it out and now my head hurts . . . :roll_eyes:

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I’ll give this a try. Thanks a ton to you both!

I don’t have fancy drawing tools…

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