Hello. I've had issues replacing a simple 3-way switch. The old one had a black, red, white, and bare ground wire coming in to the box. The red wire was connected to the common terminal (dark screw) of the old switch. I wired the new one with the black wire to the common terminal and the red and white wires to the other brass screws. When I toggled the switch, I had no luck. So, I reverted back to how the old was wired (red on to the common terminal) and it was a go - lights on. Is this fine? Is there a reason why the red and black are "flip-flopped" on the common terminal? So far, so good. I have not had any issues since yesterday. Thanks for your time.

I wired the new one with the black wire to the common terminal and the red and white wires to the other brass screws.

That was an incorrect thing to do.


So, I reverted back to how the old was wired (red on to the common terminal) and it was a go

That was the correct thing to do.


Is there a reason why the red and black are "flip-flopped" on the common terminal?

What does that mean?

Colors designate how conductors are used, white is neutral (usually), green is ground and other colors are hot. There is no rule black goes here and red goes there. They are both hot conductors. There are five ways a set of 3-way switches can be wired. By that I mean five ways electrically, not which color wire goes on which terminal. Which terminal a wire is connected to at one switch depend on which terminal it is connected to at the other switch.

Thank you very much for your time and response. I have limited knowledge of wiring and just wanted to be certain that I did not create a potential hazard. Again, thank you for the information.

Sorry, didn't mean to be abrasive. Its just that with the different ways a 3-way can be wired, it is impossible to tell why the original installer chose the colors he did.