Electrical – Why doesn’t the 3-way light circuit work in some configurations

electricallightingmultiway-switchswitchwiring

I updated some wiring in my garage. I added two 3 way switches. If there is a switch in the down position when the lights are off, I cannot flip my other switch to turn the lights on and vice versa. But, if the switches are up, the lights are on, then I can use a switch to continue to turn them off and on.I don’t know what the problem is, I believe I hooked all of the wires up correctly. Here is an explanation of my wiring.

Please note I am hooking up two 14–2 wires and two 14–3 wires.
From the power source, I hooked the common black wire to the common black wire that connects to my black screw on my light switch. From that light switch both my red and white wires are connected to the white and red wires that run to my other light switch. My black wire from that switch runs to the black hot wire that connects to my light fixture. From the light fixture, my white wire runs back to the white wire that comes from the power source. And then I have all my ground wires Pigtailed together.

I believe that is the correct way of wiring this set of wires according to what I have read and seen pictures of. I even swapped out the three-way switch That was not connected to the main power source. Does anybody have any ideas? Thank you for your time.

Best Answer

First, be clear on how 3-way circuits work. Now it's really hard to be clear in a diagram or junction box full of Egyptian spaghetti (red white black green). So we'll fix that -- thusly.

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Here is a basic 3-way diagram. Now this doesn't tell you anything that jsotola's diagram doesn't, except for one thing -- we are adding color to designate wire function.

Black and white are hot and neutral, of course. Red is a traditional/common color for switched-hot.

The two travelers are different, but interchangeable, so they can be the same color without harm - in this case yellow. Feel free to use purple or blue if you prefer, just as long as it's unlike anything else in the box.

You can't buy /3 cable in yellow-yellow-white. So we end up using the stock black white red. And I say re-mark wires using colored tape to designate function.

Based on OP's description and comments, it sounds like there are two /3 cables and two /2 cables coming into a junction box like this:

enter image description here

Here I show the usual black-white-red cable colors, but I also "use tape" to re-mark them by function. Boy, this makes a big difference in clarity. This particular box didn't have a big problem with mixed colors, but some do.

Note that by OP's convention, the native-black wire is the one on the "common" (black screw) of the 3-way.

Now, if it's not working, it sounds like your travelers are not set up correctly. I have a feeling you have them crossed with something else, e.g. At a 3-way for a wire meant for a common terminal.

Tip on 3-ways: look at screw colors. The location of the common vs. other screws is completely random. I have held two 3-ways from the same manufacturer in my hand and one of them, the common is upper left, the other, lower left. WTH? I've been tempted to try to collect all 12 combinations!