Red and Aux 3 way install Help

[texclayton]

This sounds like the situation I wired up last weekend.

3 way, line to fixture, no neutral

That’s what I tried originally. I tried it again today, but it only works when the dumb switch is in one position. I changed the Neutral & Switch Type parameters several times, but no combination worked (including the technically correct Non-Neutral / 3-Way Toggle combination). It turns out my wiring is more like this: [udHF1knGEg] The fix was to use the GE Aux switch instead of the original dumb switch in the “left” box: I connected the Load (white) from the RS Dimmer to the Load going to…

In my situation, I put the 3-way dimmer in SB2 in OP’s image, and the Aux in SB1.
The Line from the light went (through the SB1 box) to the Line in the 3-way dimmer AND pigtailed into the Neutral of the Aux.
I connected the white/Load from the dimmer to the Load coming from the light.
The red/Traveler from the dimmer went to the Traveler in the Aux switch.

Set the Power and Switch Type parameters (#21 & #22) to Non-Neutral and 3-way Momentary (or Aux depending on your UI)

Disclaimer: I’m just a noob.