Q&A for How to Wire a 4 Way Switch

The same way you would wire one light fixture with two switches. There are many ways to wire a 3-way switch. Once you pick which one matches yours, you just replace the diagram with 2 lights instead of one light.

Yes. If you have a multimeter, use the continuity setting. Pick one of the four posts of the 4-way switch to hook up the source power. Put one lead of the multimeter on this post. Test the other posts to see which one has continuity and which does not. Leave the lead on a post that does not have continuity with your initial post. Now flip the switch. Does it have continuity now? All you have to do is use two posts of your 4-way switch that alternate continuity when you flip the switch. That's all a regular switch is doing, breaking the continuity between your source power and your load.

After you restore power to the circuit, click a switch up or down to turn on the light. Click the next switch to turn off the light. Click each additional switch to make sure each switch can independently turn the light on and off.

Yes, certainly. The 4-way switch may be placed anywhere in the system. However, for efficiency and lower wire expense, you may want to replace one of the existing 3-way switches with the 4-way and add another j-box for the new location for the 3-way - attached via 14/3. In any case, as long as you realize that only the two "travelers" between 3-ways are switched by the 4-way, you should be able to figure out the rest. Hint: Two travelers from one 3-way are connected (via the 4-way) to the other 3-way, without connecting to anything else.