Problem Adding 2nd Light

I have a light on a simple switch. The switch has a black and white wire coming from the light. I am adding another light that I want controlled from a second switch. I have a Leviton dual switch (5634) that will fit in the same single gang box. However, since the power is coming into the box from the original light I am having a problem to get both working. The best I have be able to do is get both to work individually, but I am unable to have both lights on a the same time. Is what I am attempting even possible with just the two wires coming into the switch box and if so how??

 

You are going to need to run additional cables to the location of the new light. Otherwise both will operate together.

 

Welcome to the forums!

If you're saying there's only one cable coming into the switch box, that that cable is a 2-conductor cable and that the black wire and the white wire in that cable are attached to the switch, then that switch is wired as a switch loop. In a switch loop, the circuit comes to the light fixture from the panel. the fixture is connected to neutral there while the hot wire is spliced to go to the switch on one wire and come back on the other to connect to the fixture.

IDK. What wiring did you run to your second light fixture? Have you run any new wires to the switch box?

 

Yes, the original light is a switch loop. The wires to the second light were black and white. I guess I need to find a diagram of how to wire in the new light when it is from a switch loop. Any suggestions?

 

You can add as many lights as you want to the original switch. Just run them to the existing fixture box and splice the wires color-to color to the wires for the existing fixture.

To add a second switch you'll need to run a new piece of 3-conductor cable between the fixture box and the switch box. It will need to be 14-3/G if this is a 15A circuit and 12-3/G if it's a 20A circuit. Can you do that?

BTW, if your existing switch was being wired in today, it would have to be run using xx-3/G cable, in order to have a neutral in the box for motion sensors, timers and other energy-saving controls that sometimes need that.

Post back to tell us if you can install the second piece of cable. Or whether you'd like to move on to automated controls or some other solution.

Almost missed this: From the second light to where? To the fixture box or to the switch box?

 

The house is 32 years old and was wired using aluminum flex. I am pretty sure I can pull a 12-3/G cable (20A circuit) through since it only has the black and white now. However, I need a picture or diagram to know what goes where. Is there anything out there that will show this?

 

You're in LA. That's a conduit wiring jurisdiction.

Aluminum flex cable or steel flex conduit? If it's conduit, you need to have four insulated conductors in it between the fixture and the switch, where you have only two now. If you don't see room for another 3 or 4 wires in the pipe you may be looking at cable. In that case you'll need to add a second cable.

The diagrams or descriptions of how to connect everything follow the determination of how the wiring needs to be done.