The diagrams below show the conventional wiring for 3 way switches. This might seem intimidating but it does not have to be.

Video On How To Wire A Three Way Switch
Three way switch circuit diagram. The two hot wires of three wire cable connect to a pair of brass colored traveler terminals on each switch. Traveler wires are interchangeable on each switch. Pick the diagram that is most like the scenario you are in and see if you can wire your switch. 3 way switch wiring diagram. Take a closer look at a 3 way switch wiring diagram. The black and red wires between sw1 and sw2 are connected to the traveler terminals.
All three way switch and 2 way switch wiring diagrams have the same basic components. See alternate 3 way switch wiring configuration for another way 3 way switches may be wired. Wiring diagram 3 way switch with light at the end in this diagram the electrical source is at the first switch and the light is located at the end of the circuit. Unfortunately not all 3 way switches are wired the conventional way. A 3 wire nm connects the traveler terminals of the first and second 3 way switch together. In this diagram the incoming hot wire attaches to the first switchs common dark colored terminal.
The black line wire connects to the common terminal of the first 3 way switch. If you have any problems with these switches it may be best to call an electrician. In the 1st diagram below a 2 wire nm cable supplies power from the panel to the first switch box. Three wire cable runs between the switches and 2 wire cable runs to the light. With these diagrams below it will take the guess work out of wiring. If you are trying to troubleshoot a 3 way switch operation you will need to identify the function of each wire.
Wires consisting of a line a load a neutral a pair of travelers and two 3 way switches. This 3 way switch wiring diagram shows how to wire the switches and the light when the power is coming to the light switch.