I just bought a home with an unfinished basement. The framing and insulation are done, but there are 3 small light fixtures installed with no wall switch (pull cords only). I'd like to put all three lights on a switch control, and would actually like to have two switches - both controlling all three. Can I add/insert the switches to the existing run (14/2g), or do I start from scratch at the box?

Thanks in advance, Mike

 

There are many ways of doing this, but what you suggested probably isn't one of them.

What you are talking about is 3-way switches. Here's how I suggest you proceed:[list=1][*]Get at least two books on home wiring from the library or home improvement center. Read them.[*]Carefully examine the lights and the cables that connect them. On one of the three lights, you will probably see only one cable into the box. On the other two, two cables will go into the box. If this is not what you see, stop here and post back.[*]Look carefully at the writing on the side of this cable. It should say "14/2 NM-B". If it does not, stop here and post back with what it does say.[*]Now follow the cable as it goes from light to light to light. The last light will be the one with only one cable. Follow the cable back from there to the middle light, and from there back to the first light. You will make all of your modifications at this "first light".[*]Buy and install two single-gang boxes. Buy the biggest single-gang boxes you can find, probably 22.5 cubic inch plastic boxes. Nail them to a stud somewhere where you want the two switches.[*]Buy a length of 14/3 NM-B (aka Romex) cable (black, red, white, bare). You only need enough 14/3 to run between the two new boxes you just installed.[*]Run this 14/3 cable between the two boxes, stapling it at least every 4.5 feet, drilling holes to get it through studs and joists (in the dead center). Run about a foot into each box and staple it within 8" of each box. Very carefully strip all of the sheathing off the cable such that only about 1/2" of sheathing remains inside each box.[*]Strip about 3/4" of insulation from each wire, being very careful not to nick the copper.[*]Shut off the breaker.[*]Buy some 14/2 cable (black, white, bare). Run it from the "first light" to the nearest switch box, using the same techniques as the prior step.[*]Carefully remove the screws holding the first light to the box. Lower the fixture without disconecting any wires. Record everything you see on paper in case you need to reconstruct it.[*]Identify the two cables as "P" and "D". Cable "D" will be the one that goes to the middle light. Cable "P" will be the other one.[*]Go get a black magic marker.[*]Now disconnect the light and all the wires in this box, and insert your new 14/2 cable into the box as above. We'll call the cable that goes to the switch "S". Use the marker to blacken the last inch of the insulation on the white wire in cable "S".[*]Use a yellow wire nut to connect cable "P" black wire to cable "S" white (remarked) wire. Tuck this connection into the back of the box.[*]Use a wire nut to connect all three bare wires to each other. Connect them to the fixture or box as was the case before you removed the fixture.[*]Connect the "P" cable white wire and the "D" cable white wire back to the fixture, exactly as they were before (well, you could have left this connected in the first place if you wanted to). If the fixture has a white wire protruding from it, that will be done with a simple wire nut. But if the fixture has a silver screw for wire attachment, you will use a white pigtail (as was done before).[*]Connect the "S" cable black wire to the "D" cable black wire and the fixture black wire (or black pigtail to the brass screw).[*]You're done here. You might want to wait to repack all this stuff until later after you've tested.[*]Go to the switch box at the other end of the "S" cable.[*]Remark the other end of the "S" cable white wire as you did at the light.[*]Call the 14/3 cable "X".[*]Buy twe 3-way switches. These switches will have one black screw, one green screw, and two brass screws.[*]Connect the "S" cable (remarked) white wire to the black screw.[*]Connect both bare wires using a green wire nut with the hole in the end. One of the two wires will protrude through the hole and connect to the green screw.[*]Connect the "S" cable black wire to the "X" cable black wire with a wire nut. Push this connection into the back of the box.[*]Connect the "X" cable red and white wires to the two brass screws. Remark the "X" cable white wire as before.[*]Go to the other switch box.[*]Connect the bare wire to the green screw.[*]Connect the red and white wires to the two brass screws.[*]Connect the black wire to the black screw.[*]Turn the breaker back on and test.[*]If it all works, shut off the breaker again and carefully repack all the boxes.[/list=1]