Switch Junction box has 3 sets of 3 wires. Can't get dimmer to work

knockout

Hey There,
I'm trying to wire in a dimmer switch for my living room but the process isn't going as smoothly as I had hoped.

The light switch I am trying to replace only controls a single light fixture on the ceiling, as such, I purchased a single-pole dimmer switch for this application.

The dimmer switch I have has 2 black wires and one green wire. It's a Diva which is made by Lutron.

The junction box is where I run into the problem. It has 3 sets of wires coming into it. Each set of wires has a black wire, white wire, and a bare copper wire.

The white wires are all connected using a plastic twist cap thing and the bare copper wires are all connected using a plastic twist cap thing as well. This leaves me with 3 black wires to connect to the dimmer switch.

To this point, I've tried all possible combinations, but it never works properly. I always end up with one of the following scenarios:

1) Nothing works properly,
2) The living room works properly with the dimmer switch but the kitchen light stops working, or
3) The living toom light doesn't work at all but the kitchen light works with the dimmer switch.

My house is approximately 8 years old so I can only assume that the wiring was put in properly and the former tennants didn't mess around with the wiring.

Any thoughts on this one? I don't want to sit in the dark for much longer.


Cheers!

PS - I just checked the old switch and it has two of the black wires connected to the bottom (one in the hole and the other on the screw) with the third wire connected to the top.

The old switch doesn't have a green ground screw either.

J. V.

Are you sure you have a single or a 3 way circuit? Could you control the light in question from more than one location (switch)? If your original switch had three wires not counting the ground it is a 3 way switch.
Thats why you SHOULD have MARKED the wires so you could install them back like before!

Please respond to this question for further instructions.

surrogate

deleted - wrong thread

lectrichand6855

Yep !

williamj001

What it sounds like to me is that the three wires do the following:
1. Power coming in to the box(Incoming Power)
2. Power going out to the kitchen light switch box(Outgoing Power)
3. Switch Leg going up to your living room lights (Switch Leg)

The 2 wires on the bottom (one on the screw and the other in the hole) are both the Incoming Power and the Outgoing Power which need to be connected together with the one of the black wires going to the dimmer(check the instructions on the dimmer, one black wire might be specifically for the power). The switch leg (the last black wire in the box) needs to be connected to the second black wire on the dimmer. The Green wire on the dimmer connected to the bare copper wires from all 3 cables coming in. It would help alot if you posted a picture of the old switch to determine if it is a Single Pole switch or if it is infact a 3-Way switch(one light, switched from 2 locations.)

220/221

Simple.

Two of the black wire go together (power in/power out) along with one black from the dimmer. This gives you power in, power out and sends power to the dimmer.

The remaining black connects to the other black from the dimmer. This sends the power to the fixture.


On the original switch, the blacks that were on the bottom are the power in/out.

Hook the dimmer green to the bares.

knockout

Hey,

Thanks for the response. Yes, the light in question can only be controlled from the one switch. It isn't a three way switch like I have in my upstairs hallway, which I can turn on from upstairs or the main floor.

I've hooked everything back up so it is working properly with the old switch.

As I said, I have one black wire connected to the top screw of the old switch and two black wires (one inserted into the hold and one connected to the screw) connected to the bottom.

Here is a picture of the old switch which is now connected with everything working:


Here is a picture of the junction box with the three sets of wires inside. You'll see two yellow connectors inside. One connects the three white wires and the other connects the three bare copper wires.

spark plug

Your posting name sounds like it has French origins. In English, (l'Anglais) it sounds as follows; "Lektreeshon...d! Since your only comment was "Yep", there's nothing else to comment about!
p.s;This poster is fascinated (besides Technology and the practical application of same) by word origins. Since this is PRIMARILY a DIY site, most of the comments and questions are about the application of technology in our everyday lives. But we can [and DO] stray occasionally to other topics of discussion!Don't Drink and Drive!!!

knockout

Hey,

I just wanted to chime in and let you know that everything is now working properly.

Thanks williamj001 and 220/221.

You both told me the right way to wire my dimmer switch. Now all the lights are working as they should.

Thanks again!!!

Now I just have to clear some wire out of the junction box because it's so tight that the dimmer barely fits inside.

Cheers!

spark plug

With all due respect to J.V. It's simply clear that we're not dealing here with a 3 way switch and circuit. The original poster stated that "There were Two Black wires connected to the same terminal. One, on the Screw and the other inside"! If this circuit were multi-location controlled, the wires would be on separate terminals on a 3-way switch!Don't Drink and Drive!!!

J. V.

Correct spark plug. I should have paid more attention to the the post. I did not see/read the 'two wires on one terminal". I saw three and assumed. Thanks.

ronz

I'm having the same problem, but my switch is not connected. Anyway to tell which are the power in/power out black wires that need to be connected together?