Any idea what's going on in this lighting wiring circuit?

When we moved into our current house, there were already two recessed spotlights in the ceiling above the fireplace to shine on a painting. There was also a ceiling fan with lights. The recessed spotlights only had one switch on one wall. The ceiling fan had three switches (3-way) on three different walls.

I wanted to add more recessed spotlights to two other walls for two more framed pieces of art. I've already added one spotlight to the existing wiring, running off the same single switch. I'd like to have a dimmer switch for the next two spotlights, and have the dimmer switch on the wall opposite the existing recessed spot switch.

In the receptacle in which I want to install the dimmer are two switches. One is a three-way for the ceiling fan, and the other doesn't seem to control anything. There are two leads on the bottom of the non-functioning switch: one black lead coming from the live feed, and one white one going to the ceiling fan. The top (switched) lead goes back to the three-way switch on the opposite wall.

That top (switched) lead has no effect on the ceiling fan. I don't understand why it's there at all. And if there's supposed to be current going through the white wire to the ceiling fan, why not just join the black and white leads that are at the bottom of the right switch together with a wire nut? Why use a switch to join them?

There isn't an inlet in the box for a fourth cable to come in, but I could make one, or put the fourth cable together with another one through the same hole. But first I'd like to figure out what's going on.

Here's a diagram of the wiring. Any ideas what's going on?

 

Welcome to the forums!

Two of those switches will be 3-way switches. The third switch is a 4-way switch.

Which is it? Does the white wire go to the fan or to the other switch?

Disconnect the wires from that switch and cap them off. Restore the power and test to see if everything still works the way it did before. If so, you can use that location for the dimmer switch for your fourth spotlight.

 

Nashkat1, thanks for the reply.

The white wire at the bottom of the single switch goes to the ceiling fan. The black wire at the bottom of the single switch comes from the hot lead from the breaker box. The top wire goes back to the three-way switch on the opposite wall, but doesn't appear to do anything.

If I disconnect the white wire at the bottom of the single switch, the ceiling fan won't work. Ditto for the black wire at the bottom of the single switch. Whoever installed this used that bottom connection as a glorified wire nut. Disconnecting the top wire on the single switch, the one that goes back to the three-way switch on the opposite wall, has no effect on anything.

I can't see any reason not to connect the white wire (but taped red at the end) to the hot post of a dimmer switch, along with the black wire, except that I don't know if it's safe to run a fourth line of romex into the box. I'd have to enlarge one of the holes to allow for two romex cables, or drill another whole. Alternatively, I could replace the box with one with four inlet holes for cable. That I'm sure would be fine.

I just can't figure out why there's a switch with a wire that just goes back to the three-way switch for the fan, when that single switch isn't for the fan.

I've had older homes all my life, and I'm used to bx and conduit and galvanized boxes. When I went up to the attic for the first time, I was shocked to see romex just running all over the place, not stapled down, and very sloppy.

 

For clarity, are you saying that this is a single-location switch - aka a single-pole single-throw (SPST) switch - with two terminals and ON/OFF molded into the toggle? And that the white wire connected to it goes to a box with a 3-way switch in it? If so, how is that white wire connected in the second box?

It also sounds like you're saying that this house is wired with Type NM cabling. If so, how are the other conductors, in the two cables that have wires connected to this switch, terminated?

How did you determine that the black wire is a hot feed from the breaker?

Some pictures might help us see what you have. See How To Include Pictures.

Tech Note 1: Electrical switches can be mounted in any orientation and have no "top" or "bottom."

Tech Note 2: A 3-way switch is also a single-pole switch. It differs from a SPST switch by being a double-throw switch (a SPDT switch). A 4-way switch is a double-pole double-throw (DPDT) switch.

 

The two switches above have the graphics reversed.
"To second 3 way switch and" and "to ceiling fan" should be reversed.

 

The switch on the right is a single pole, single throw. The white wire is connected to the same terminal as the black wire coming from the live feed. The white wire doesn't go to another switch box; it goes to the ceiling fan wiring connections in the attic (ceiling). I followed that length of Romex in the attic from the switch box to the ceiling fan.

The black wire that is connected to the same terminal on that SPST switch comes from the breaker. It's part of a two-wire (plus ground) NM romex cable, and not from any of the ceiling fan switches. It's hot all the time, no matter what position any of the ceiling fan switches are in. The top (switched) black wire from that SPST switch goes back into the NM cable that goes to the three way switch on another wall.

I"m saying "top" and "bottom" so as to reference my diagram above. I know that switches don't have tops or bottoms.

The "top" wire on the right hand SPST switch can be disconnected, and has no effect on the ceiling fan operation from any of the switches, or any other device or outlet in the house. That's why I don't understand why it's there, and why the white and hot black wires are connected to the bottom pole on that switch.

I don't think a photo would be understandable, as there's too many wires in a small box. That's why I created the diagram above. That's exactly how the switches are wired.

 

I re-labled your illustration. The circuit makes perfect sense but not the way you had the switches labeled. It's very easy to follow a piece of romex to a location and get it mixed up with another adjacent one.

Look at my illustration. If it is incorrect....I'll remove it.

Removed incorrect illustration

 

Yep, that makes sense.

Can you control the ceiling fan motor with anything other than the pull chain? Does the motor get switched on and off with the lights?

Given PJ's diagram, it looks like you could send always-hot power to the fan motor and use the location where the SPST switch is now for the dimmer for the recessed spot. Or you could expand the box to 3-gang, replace the SPST switch with a fan motor controller and install your new dimmer in the third space. More room for wires in a 3-gang box too.

 

PJMax, that was a good guess, but that's not the case. The ceiling fan lights and the motor are on the same circuit. Turn off any of the three-way switches and power to both the lights and motor are turned off. The SPST switch has no effect on the lights or motor or anything else.

The ceiling fan lights and motor are operated by the wall switches, pull chains and remote control.

That top switched black still goes nowhere.

 

If your circuit is not how I've drawn it then you have some work ahead of you because it would then seem like someone just wired the circuit using whatever colors they wanted for anything.

Your drawing shows a neutral going to three way switch and no neutral to the fan/light.

 

How many cables go from the 2-gang switch box to the fan box? Can you work the switches so that only the black wire carrying switched power out of the box is hot, and then trace that cable and tell us where it goes?

A circuit originates at a fuse or a circuit breaker. Do you mean the same set of switches?

Someone may have decided to replace a dual-switch setup with the remote. In doing that, they may have also decided to have the remote powered by the 3-way/4-way switch group and to cap off the wire from the SPST switch that used to feed the fan.

 

I should have said that the ceiling fan motor and lights are on the same switches, not the same circuit. There's several lights on the circuit.

The remote has controls for the fan speed, as well as on and off for the fan, as well as brightness controls and on and off buttons for the fan lights.

I'm installing the last two of five spots this weekend (it's hot in the attic in the afternoon, so it's mornings for that job). I'm going to put the last two on the same switch as the other three. The switch is a dimmer. If the light level of the last two is satisfactory, I won't bother adding a separate dimmer switch for those two. If I have to, though, I'll put it in place of the go-nowhere SPST switch.

This house was built in 1990, and there's a lot of oddities in the wiring peculiar to that time.

 

It sounds like you can access the wiring above the fan. If so, I would look for the end of the wiring from the dead SPST switch there. If it is there, you've got the answer, and you can either relocsate it or abandon and replace it.

 

Actually I can't. The ceiling fan is mounted to the bottom of one of the 2" x "8's in the attic. There's no junction box, just the wires going into the fan. Directly below the ceiling fan is an 8 foot pool table I bought and had installed in December.

If I get a cool day I may go up there again and look at what's coming in to the fan and from where. Near as I can tell now, the only run of romex going to the fan is the one from the right side of the box in my diagram.

If any pro's go up in the attic, they're going to laugh at the job I did. The romex is stapled every three to four feet, and run low on the joists, out of the way of feet, hands and other things that could snag on it. No cable lying across the joists or just hanging from a board.