Electrical – Wiring a box that has two switches to multiple lights

electricalswitch

I have four outdoor lights that are controlled by a switch. I am replacing that switch with a Leviton Decora Smart switch. I can't seem to figure out how to wire it properly, hence I'm asking for help!

In that same switch box is another switch which controls a single light. Here's an image:

Wiring conundrum

Full size

I think I've figured out which is line and which is load. The black wire coming out of #3 is line power. The black wire returning to the bundle of wires is load to the lights. I suspect I may be wrong here because the black wire coming from the switch on the left also goes to the bundle of black wires. The red wire going to the switch on the left is coming from #3 as well.

Basically, the switch which was on the right had two black wires, one of the black wires coming from #3 and one coming from a jumper connecting to the bundle of black wires.

I powered it on and nothing happened. But, nothing shorted either.

Can someone please help me in wiring the dimmer on the right? I haven't had any issues before. This is the first time a switch wiring situation has stumped me. Also I'm a bit sick so I'm kind of hazy (excellent time to work with electricity btw).

Thanks!

Best Answer

1,2, and 4 only seem to feed into the wire nuts, one of these is your power source, the other two are feeding power elsewhere.

It appears that your black wire nut is line power, your left switch controls a load on the red wire on #3 and the right switch controls a load on the black wire in #3. This is likely split off elsewhere to the separate lights, sharing the neutral on #3.

So it appears that your switch line/load is possible reversed.

Also your smart switch likely needs a neutral to function, which doesn't appear to be connected, from the white wire nuts.