When we moved into this 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 want to add more recessed spotlights to two other walls for two more framed pieces of art. I 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?