Black screw on 3 way switch. What is common in the diagrams above and with any 3-way switch circuit is that the power hot wire coming into the circuit will always go to the common terminal of the first switch.

black screw on 3 way switch


Four Wires Inside each box you should discover four wires that connect to each 3-way switch.

black screw on 3 way switch

The red should be terminated on the other side.

black screw on 3 way switch

There should be a cable entering each box with a red, black, white, and ground.

black screw on 3 way switch

If you get the impression we all kinda "make it up" in 3-way switch circuits -- you got it!

black screw on 3 way switch

One minor correction:

black screw on 3 way switch

Thinking about colors is useless.

black screw on 3 way switch

Related

black screw on 3 way switch

So you might find cases where power goes to the light first, or other strangeness.

black screw on 3 way switch

The incoming power wire yellow in this example has the three wires.

black screw on 3 way switch

Because of this, the switch may also require a neutral wire.