I've got 3 switches controlling some can lights in the living room. I believe the configuration goes like this: breaker box--->1st switch--->2nd switch--->lights--->3rd switch. I've searched this forum, looked at Larry's diagrams (which have been very helpful doing my other switches), and read sundry other articles, but am stumped on this one.

The 3rd switch box is a single gang with only 1 blk, whi, and red. I'm resolved to using just an ordinary switch there if it'll work with the master and slave I've got for the other two switch boxes. The 2nd switch box has 2 blks, 2 reds, 2 whi. In there the 2 blks and 2 reds were connected to the original switch, and the 2 whi's joined together with a wire nut. Now the 1st switch box is a dandy. In this 3-gang box is the switch in question, along with a switch for a ceiling fan, and a switch for the ceiling fan light. Instead of trying to type out how it goes, I'm posting a diagram (sorry it's not near as neat & pretty as Larry's) at
I used blue for the white wires, and the orang blobs are wire nuts.

Any help would be greatly appreciated. I worked on this about 5 hours last night with no luck. At one point I did have it to where you could turn the lights on and off at the master switch, but you had to hold th switch in until the lights reached 100% on and 100% off.

You can't mix an ordinary switch with the rest.

I don't see any way you can put a slave in that last box unless you run some additional wires.

How many conductors are in the cable between the 2nd switch and the lights? If it has Blk, Wht, & Red then you can run power and nuetral to the last box and replace that switch with an in-wall keypad transmitter. If you only have blk and wht then you'd need to run a new power line to that third box from somewhere such as a nearby outlet before you could add the keypad there.

I thought I had read somewhere on here that you could mix "ordinary" switches with PCS switches.

Anyhow, the wire from the 2nd switch box to the light (I'm assuming that's where the wire goes) is 12/3 w/grnd. The same coming into the 3rd switch box. After thinking about it some more, could wire #4 (in my wiring diagram) be the one going to the light? That seems to make a little more sense - explaining the purpose of that wire in that box.

You can use run of mill X10 switches with the PCS switches but not ordinary light switches. At least that is what the instructions say that come with the PCS switches.

You can not mix ordinary switches with PCS unless all you want is a way to completely deactive your PCS switches.

You really need to nail down what wires are going where. Shut off the power and get out your multimeter.

With a 12-3 running between all boxes you can at least go with the in-wall keypad transmitter in the last location. This will give you X10 control of that circuit plus you can use it to activate up to seven scenes, depending on which keypad you choose. Unless the last switch location is chained off a different box, I don't see how you can put a slave there.

If I were doing it, I'd go with keypads any of the slave locations where scene control would be convenient.

I'm not really wanting a keypad at this point (or is that can't afford one? - we just got through building our house). But, from what I understand, I could put just a "plain 'ol" x-10 switch in the 3rd box, and then all of the switches would work (PCS included)? And since I'm a newbie at electrical wiring, how can a multimeter help me determine what wires are going where? Thanks for your help!!!

No, you can't put a plain X10 switch in with the 3-way ciruit. If the wiring is as I think it is your choices are as follows:

1. Run and extra romex to that last switch location
2. Replace that last switch location with a keypad
3. Take thet last switch location out of the circuit

In-wall keypad transmitters start as low as $21.07. Look at the XPT1 at [Link: homeautomationnet.com]

To trace the wires you'd turn off all the power then use the multimeter to determine which romex goes to each box by shorting one romex's black and white wire (make sure the power is off) then looking for the shorted wires in the other boxes.

Ok. Sorry to keep asking so many qestions, but if I go with option 1, to where do I run the new Romex from the 3rd box?

You could run it from the third box to any of the other switch boxes.