These switches are a bit more confusing and you may find yourself getting a little frustrated... relax. Take your time, mark the wires properly and you will not only be successful, you will stay sane.
The first thing you will need to determine is where the power is coming from and where the switches are positioned.
I have a few examples below that should cover pretty much any situation.
Just click on the link to get a larger 3 way switch wiring diagram...
Option #1: Power to switch -- to switch -- to single light.
In this first example, the power is coming in to the first switch, flowing along to the second switch and ends at the light. The ground wire will always be attached in each box and flow right to the end fixture.
Option #2: Power to switch -- to switch -- to light -- to light...
This option is very similar to option #1 when wiring a 3 way switch. Here I am showing how to hook some lights up in series. If you need more than two lights, just keep pig-tailing the white and black wires to keep the circuit going.
Option #3: Power to switch -- to light -- to switch.
This may be one of the most common way to wire a 3 way switch. Think of your staircase or hallway. Light switch at one end, lights in the middle, light switch at the other end.Trace the wires carefully in the diagram so you can connect them to the proper locations.
Option #8: Power to light -- splits to two 3 way switches
Here is another example of wiring a 3 way switch with the power coming from the fixture. I is similar to Option #3 only with the power coming into the light fixture.
This option is helpful if you are adding a light to an existing building and it is easier to drop all the lines down from an attic instead of trying to get wiring up from a finished basement or trying to fish wire up two stories.
Option #9: Power to switch -- splits to switch and to light
In this scenario the power comes into one of the 3 way switches. It then splits to a light fixture and another 3 way.
Keep in mind that the maximum allowable wires in a standard size electrical box is five (5). In this option you will have seven (7) wires in the first box. Not to worry, you can purchase and oversize receptacle box just for such an occasion.
Hey, doing it yourself is great but if you are unsure of the advice given or the methods in which to job is done, don't do it. This site is merely a collection of how some people do home improvements. There is no way we can anticipate every situation and we do our best to inform of any risks for each job. Be sure to check local building codes for proper installation and permits. If in doubt, hire it out.