Latest Discussions : Electrical & Lighting


03:03PM | 09/24/05
Member Since: 03/04/03
44 lifetime posts
I am trying to connect a 4-way switch to control a stairway light, but am having no luck. Here's the situation.

Three switch boxes:

Switch box at top of the stairs contains: One 3-wire (black, red, white) and one HOT 2-wire (black and white).

Bottom of the stairs, side 1 contains: two 3-wires.

Bottom of the stairs, side 2 contains: one 3-wire.

What I don't know - what is buried somewhere in the walls or ceiling - is where/what wire goes to the actual light.

When everything is disconnected, the light is off, and the 2-wire at the top of the stairs has power.

At the bottom of the stairs, side 1: the two 3-wires (I think) go into the four way switch. The switch has four screws, two marked "In" and two marked "Out". I put the red and white (from the 3-wire from top of the stairs) into the two "Ins", and the red and white from the 3-wire that goes to the bottom of the stairs, side 2 to the two "Outs". I jump the blacks together.

At the bottom of the stairs, side 2, I have a 3-way switch. I have the black wire on the black screw. And the white and red on the two brass screws.

The top of the stairs, where I have the 3-wire, and the HOT 2-wire, totally confuses me. No matter what I try, I trip the circuit.

Can anyone lend some advice?

Thanks is advance,


doug seibert

03:17PM | 09/24/05
Member Since: 08/10/02
842 lifetime posts
Visit here........check back if you're still stuck.....

what I couldn't tell from your description .....was this circuit working correctly at one time......where does the light connect.......


03:29PM | 09/24/05
Member Since: 03/04/03
44 lifetime posts
Thanks for the info.

The circuit was working correctly when I started. When I started, the circuit had two 3-way switches, I am adding the 4-way (third switch).

I also don't know where the light is connected. The HOT line coming into the 1st switch box is always on, but when nothing is connected to it, the light is off.

This seemes to indicate that somewhere in the 3-wire line, a 2-wire branch is going to the light.

But I don't know for certain.



04:14PM | 09/24/05
Member Since: 04/25/05
1915 lifetime posts
Is this what you have orginally. A 2 wire cable, a 3 wire cable, and a 3 wya switch at the top of the steps?

And at the bottom a 3 way switch with 1 3 wire cable?

If what you might have switch leg wiring.

You said that the 2 wire cable was HOT. How did you test it?

Howver with that there is no way that you could mis wire it so that it would trip the breaker unless the you got something connected to the ground wire.

Here is another system that you might have.

Now that has light in the middle.

Note that when you get to switch legs that the white is now the Hot and the black is the switched hot. But the white is suppose to be remarked with black or red tape. Often that is not done. Often the black and white or reversed.

Likewise in the 2nd you will find colors codes on the 2nd one different.

If you an easily open up the light box it will be real clear which wiring you have.

If you have the switch leg then this is the 4 way version.

Replace the switch at the bottom with 4 way and put the 3-way in the new location.

If you have the 2nd type with the 3 way cables to the fixture you would extend it the same way.

Replace the existing 3way with a 4way. The existing cable R & W will connect to one pair of terminals. NOTE THIS IS USING THE COLOR SCHEME SHOWN IN THE DRAWING AND MARKING (TAPE) THE WHITE WIRE.

The other pair of terminals will connect to the R & W of the cable going to the new location. And the black will be jointed to the black from the new location.


11:00AM | 09/25/05
Member Since: 03/04/03
44 lifetime posts
Thanks everyone for your advice.

The problem was in the attic. There were 3 high-hat lights all on this switch. And when I checked the attic, the junction box was a "rats nest" of 6 bx cables, 2 three-wires, and 4 two-wires. The prior owner knew enough to be real dangerous and left me with a mess. One of the three wires had it's black and red going to the high-hats.

Once I cleaned up that box and seperated out the extraneous lines, I was left with just 2 three-wires, which I just connected together. These were from the primary 3-way switch to the lower level 4-way switch. And then 2 two-wires, one from the light (I ditched two of the high-hats), which I then extended with a second through the junction box and into the primary 3-way switch.

Then all I had to do was follow the direction in this link:

Thanks again,


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