How can I combine three switched circuits into one? [closed]

Question

I have 3 light switches in my basement. Each one operates 4 recessed lights. I'd like to get all the lights on one switch. Is it as simple as getting an appropriate sized switch and combining the wires from the original switches with wire nuts to one switch instead of three?

Answer 1

You can determine if it's possible by checking the following:

• The lights are all on the same breaker. Turn off the breaker that controls any of them, and they should all turn off.
• The lights are not on switch loops. If you have one cable entering the junction box, with (usually) a black and white wire and those two wires, from that cable, are connected to one switch, that is a switch loop. That light cannot be combined with others in the simple way you want. To confirm that you do not have switch loops, you should have a bunch of cables with all their white wires connected together, each of their black wires except one connected to the various switches, and the remaining black wire connected in a chain to all the switches.

Both the above problems are unlikely. Multiple circuits to a switch box just for lights and ganged switch loops are not common. If you have either problem and want to solve it .... but with a lot more effort ... ask a new question with lots of detail.

Otherwise you can do what you want. Yes, the black wires from the lights that are connected to different switches should simply all be connected to one of the switches using a wire nut and a short piece of wire. The chain of wires connecting power to all the remaining switches should be removed.

I'm not sure what you mean "appropriate sized switch". Some dimmer switches are limited in power but most on/off switches are capable of switching all the lights you can fit on a 15A circuit. If you're using a dimmer switch for this ... ya, buy one that's big enough, or just replace all your bulbs with LEDs.

You'll also have to buy a cover plate with blanks where the disused switches were, or, leave them in place but unwired. If you can't find a suitable cover plate, use a Decora style switch for the new one, a Decora cover plate the right size for your junction box, and you can buy blank filler plates for the empty slots. You can also install receptacles in the empty slots, powered by the same circuit as the lights, but if you do that then the receptacles will need GFCI protection.