Help Wiring Three-Way Switches

[weekley14]

Hello - My girlfriend and I recently purchased our first house and I have a question regarding a light that stopped working.

We have an outdoor security light that is controlled by two three-way switches, one upstairs and one downstairs. We are doing some minor decor changes and I purchased two new three-way switches to replace the old. However, like an idiot I did not mark down what wires went where and now cannot figure out the way they should be. Attached are some pictures of what I have going on:

This illustration shows the current layout of things. (yellow is the cable shroud)

• The two black wires in the "Downstairs" switch were twisted/taped together and folded into the back of the box, not connected to the switch.
• The three remaining wires in the "Downstairs" switch were all connected to the old switch.
• I took off the outdoor light cover and it only has one white wire and one black wire coming into it.
• The "Upstairs" switch had all three wires connected to the switch
• Looking into the switch boxes, I can tell the wires are grouped into cable shrouds as shown.

In an effort to find the hot wire, I turned the breaker on and began testing with my multimeter. I was unable to find power on any of the loose wires in either of the switch boxes. I then removed the tape from the two black wires in the "Downstairs" switch box and found the black wire coming from the two-wire cable had 120v. I have also confirmed continuity between the red and white wires in the three-wire cable when the two are connected directly to each other in the "Downstairs" switch box and the probes of my multimeter are touched to the red and white wires in the "Upstairs" box. This light and switches seem to be the only things connected to this breaker. I do not know if there are any other wiring connections (junction boxes) between the switch boxes and the outdoor light.

Any help you have on wiring the switches would be greatly appreciated.

Here are two actual pictures of the switch boxes:
Downstairs Switch Box: (I reconnected the two blacks as they were originally)


Upstairs Switch Box:

[pushkins]

It's kind of confusing, black is normally the common, red are normally the travelers and the white normally would nut together and travel through to the light fixture.
What you have described has the blacks traveling through.

Hayzee is the resident electrical pro. (and a very good one at that) so wait for his solution.

[HayZee518]

3 way and load

please go to the electrical forum section, illustrations, 2nd diagram. I believe this is what you have. just follow the colors on the diagram & you should have no problems.

[weekley14]

Thanks for the speedy responses both of you!

HayZee - is this the illustration you are referencing?



Following the colors in the diagram:

• I should connect the red and white wire from the 3-wire cable to the traveller screws of each switch.
• Connect the black wire of the 3-wire cable to the common screw of the upstairs switch

This is where I get lost. The diagram shows I should connect the black wire from the 2-wire cable to the common screw of the downstairs switch. However, the black wire from the 2-wire cable is connected to the black wire of the 3-wire cable.

Should I disconnect these two black wires and connect the 2-wire cable's black wire to the common terminal? If so, what do I do with the remaining 3-wire cable's black wire and the 2-wire cable's white wire?

Or should I leave the two black wires connected and connect the white wire from the 2-wire cable to the common terminal of this switch?

Sorry for all the questions. I'm a novice, but I generally understand basic wiring. This three-way stuff just throws me for a loop. I sincerely appreciate the assistance.

--Joe

[HayZee518]

3 way

I looked at your pictures.
one box has only a three wire in it.
the other box shows a two wire and a three wire.
question: is the two wire going to the load?
is the two wire the hot?
does the fixture box [where the light is] have more than two cables run to it. if so, this will change the wiring of the switches.

[weekley14]

I believe the two wire is the hot. When I removed the wire nut and tested each wire for voltage with the breaker on (one probe on the ground wire in back, one probe to each wire in turn), the 2-wire's black wire was the only one with 120v (approx). This wire was connected to the 3-wire black when the switch was removed.

The load (two bulb outdoor light) only has a single 2-wire cable going to it. With cable white connected to fixture whites and cable black connected to fixture blacks.

[HayZee518]

screwed up three way

after consideration of what you have and what there might be, I come to the conclusion that there is a hidden junction box somewhere between your fixture box and the two three way switches. that's the only thing left!
following is a diagram of that scenario.
evidently the hot wire is spliced into the three wire and is being brought to the junction box to be spliced to the load hot of the fixture.
the whites are being switched.

[weekley14]

Thanks for the follow HayZee.

I believe your last illustration is the correct one, as when I hooked the switches up as you show and put new LED bulbs in the fixture, the lights came on...for a short time.

Something is causing the breaker to trip (this could've been my problem all along). Next time I am off I will begin working through the attic and basement to see if I can trace the wires and find a problem.

It may be the light fixture itself, as the breaker doesn't trip when there are no bulbs in the fixture. Whether the wires are connected to the switches or not doesn't seem to play a part as the breaker did not trip until bulbs were installed.

I'll reply back with what I find in the next couple weeks.

Thanks again for everyone's help. This forum is fantastic!

--Joe

[pushkins]

If the breaker only trips when there are bulbs in the fixture then that is where your problem is. It's not uncommon for cheaper exterior lights to have issues like your have.