Connect the ground wire to the green screw. Connect the wire marked common to the black or dark colored screw.

3 Way Switch Diagram Multiple Lights Between Switches
How to wire a three way switch. Run power wire into one of the boxes. Add an electrical box for the second 3 way switch in the basement. Should be your two conductor. Wire nut the neutral white wires together. Its likely youll also need to replace the. Attach the black power cable from the wall to the general screw black in the three way light switch.
Turn off the correct circuit at your electrical panel. When wiring a 3 way switch first screw the terminal screws of the new switch until they are difficult to turn. How to wire a three way switch step 1. Connect the two remaining traveler wires to the two brass or light colored. Hook the curled end of the wire under the screw then tighten down the screw to hold the wire firmly in place. This is the existing white neutral wire coming into the box and the new white neutral wire from the 3 wire romex youre going to use to connect the other 3 way switch you will install in a minute.
Install larger electrical boxes. You will likely need larger boxes than you already have if you are replacing a regular single pole switch. Feed power wire thru either one of the boxes. Either way complete these five steps for 3 way light switch wiring. Run 2 2 wire conductors between the two boxes. This first step will eventually send power directly to the light fixture.
3 way switches involve more cables so you will need a little more room to work. You will run the three conductor wire from the box you just ran. Run three conductor wire between both boxes. Its likely youll also need to replace the.