My house has two switches in a 3-way circuit that controls two light fixtures. The lights are physically located in between the two switches.
Here's a diagram of all the wires I see inside the two switch boxes and the two light fixture boxes:
This layout mirrors the physical layout of the four boxes.
- Wavy symbol: a "bundle" of wires coming into the box
- Small tan circle: plastic connector joining wires together
- Rectangle: light switch
- Bright yellow circle: light fixture
A single bundle of wire containing black, white, red, and ground. The ground is tied to the switch next to it (which is on a different breaker).
There are 3 bundles of wire coming into here:
- A: Black, white, ground
- B: Black, white, red, ground
- C: Black, white, ground
Things that are tied together:
- All of the ground wires
- All of the white wires
- Two black wires
- A red wire and the other black wire
A single bundle with black, white, and ground
Two bundles of wire come into the box:
- Black (not connected to anything), white (connected to switch via red wire), and ground
- Black, white, and ground
The grounds are tied together.
Unlike everything else in my house, these don't have the twisted-together neutral wires inside the box (sort of like this picture: https://i.stack.imgur.com/k5RZu.jpg)
Additionally, although this circuit is on the bottom floor, the same breaker also cuts power to lights on the second and third floors (towards the rear of the house, which is also where
Switch 1 is located). Not sure if that is relevant.
The black wires inside the switch boxes are definitely hot on both ends (when disconnected from the switches).
The red wire is not hot at switch 2. My non-contact voltage detector could not give me a consistent reading on the red wire at switch 1.
Any thoughts on how this might be wired? I ultimately need to know which wires at the switch boxes are:
- Line (connected to breaker box)
- Load (connected to fixture)
- Neutral (if they exist)
Any other details or hints about this wiring would also be appreciated.