I’m struggling to figure out how to wire up a Dimmer (Blue) and Aux switch (I have an extra dimmer I can use instead, if necessary) in a 3way setup. I’ve tried a bunch of things, but can’t get it working right.
The existing wiring looks like it’s the same to both switches, so I’m pretty sure it’s a deadend 3way with no neutral setup with both switches going up to a junction box. But I’m only 90% sure about this.
Switch 1:
Switch 2:
Any ideas?
If you are 100% confident that there are only 2 switches controlling the light, then they likely both are run from the light box.
You will need to determine which red wire is your Line and which is your Load, as you will need to install the Dimmer in the box with the Load wire.
Note, these following instructions only apply if there are only 2 switches on this circuit and both switches are fed from the light, using the black and white wires as travelers between the two boxes. This is also under the assumption that the illustrated wiring is correct and both “dumb” switches work as shown. It is up to you to verify if this is correct before proceeding.
At the box with the red Line wire: Auxiliary Switch
You will tie both red and black wires together connecting them into the Neutral terminal on the Aux switch. Neither of these will be neutral, instead they will both be full time Live. You will then connect the white wire to the Traveler terminal. You should also mark the white wire with black tape to indicate it is infact not being used as a neutral.
At the box with the red Load wire: Main Dimmer
You will tie the black wire into the Line terminal, the white wire into the Traveler terminal, and the red wire into the Load terminal. Again, you should also mark the white wire with black tape to indicate it is infact not being used as a neutral.
That got the switch to work and both the dimmer and aux now control the lights properly.
But the switch seems to be frequently rebooting and the bulbs (Hue) have some intermittent flickering, I’m guessing this is because of the non-neutral setup and I’ll need to install a bypass in the two fixtures controlled by these switches.
As you are using the switch in a non neutral connection, you may need to add a bypass to increase the load on the switch so it will receive enough current to remain operational.
Something like this:
You would wire this up between the hot and neutral at the light. You only need it at one light though, not necessarily both.
You could swap out the smart bulb with an incandescent bulb to increase the load to test before buying and installing. If the switch stays steady and working, then that is likely the issue.
The bypass worked! Thanks!
