Fun With Switches

In our house, we replaced all the old almond colored, “small dip” light switches with the more modern, “rocker” kind (white) pictured at right. These are very easy to swap out in the case of two-way switches. In the hall, however, we have three switches that control the hall lights. Each switch, when flipped, turns the hall lights into their opposite state regardless of the position of the other switches. Simple right? Well, if you remove the old switches and lose track of the positioning of the wires, not really. I fiddled around with the wires on and off for the last month and finally decided that I was going to make this work without having to resort to an expensive electrician. (That last pun was completely unintentional. I swear.)

To start, I made a diagram in the venerable OmniGraffle software for Mac OS X that I used all of the time in my instrumental analysis course last spring. A thumbnail of that diagram is pictured here: click the image to view the full-size version. With this diagram, I knew how the switches needed to be connected together, but I had to decipher the wires that were emerging from the electrical boxes for each switch. No small task given the seemingly random colors and odd bundles presented before me.

After staring at this diagram from a while, I realized that each of the two 3-way switches had a bundle of wires with 2 stripped wires for connection to the switch and another bundle with only a single wire stripped for connection (load). With the two 3-way switches potentially connected properly, I only had to realize that each of the two bundles coming out of the box for the 4-way switch connected to each side. I was right, and it works properly now. I big red line now sits atop that item on my rather long to-do list.