Re: 3-way dimmer
I don't think that the presence of a 4-way switch is what is preventing the circuit from working. For my part, I have never come across a 3-way dimmer arrangement. When you say that you can?t get it to work, what do you mean? What did you expect to happen that is not happening? What does happen when you operate the set of three switches (i.e., the two dimmers and the 4-way)?