There is a way to wire a light fixture controlled with two 3-way switches using only 14-2 cable. Run a length of 14-2 cable from each 3-way switch to the light fixture and a third one between the switches to act as travelers. This is not an optimum method for wiring this arrangement, but it is possible in a pinch, if no 14-3 cable is available. This method leaves an unused conductor in each of the cables linking the light fixture to a switch, each of which must be tied to ground at both ends to indicate they are not carrying current. The conductors that are used must conform to the color convention for hot and neutral conductors, and any white conductors that are hot must be wrapped in red or black tape.
It's important to remember that the travelers and switches must always be situated between the hot electrode of the power source and the load (light fixture), to prevent any of the wires in the light fixture from being live when the switches are off (no current flowing in the circuit). Also, if metal boxes are used, the two cables must run through the same hole in any box they enter to avoid problems with eddy currents.
A variation of 3-way switch wiring employing 14-2 cable is one in which two widely separated light fixtures are controlled, such as at the top and bottom of a staircase. In this variation, the light fixtures must be connected in parallel, necessitating that an additional conductor be run between the fixtures. As a result, some parts of the circuit will contain four conductors, which can be provided using two lengths of 14-2 cable, while other parts will need only three conductors, depending on the relative locations of the light fixtures and switches
If the switch has a black screw this is a 3way switch. On a 3way circuit on one switch you connect the black power wire to the black screw, and on the other end of the 3way circuit on the other switch you connect the black wire coming from the light to the black screw.
you will need 2-3way switch and 2-4way switch
You can't. You will need a 3way switch at each end with 12/3 or 14/3 wire run between them. Power at one switch and light wire at the other switch.
The two black wires go to the other 3-way switch. The red wire goes either to the load or to the power, and the red from the other 3-way switch goes to whatever's left.
See sources and related links below. For two lights just parallel the feeds from the first light with a two wire cable to the second light.
If I am correct I think you are wanting to know how to connect a 3 way switch where you can turn off an light at 2 locations. At one switch you run a 12/2 wire from the switch to the light. There is no power at this switch. At the other switch you have your a power input wire. Run a 12/3 wire from one switch to the other. Connect all the whites together and shove them back in the box at the switch with the wire going to the light. At the switch with the 12/2 wire going to the light, connect the black 12/2 wire coming from the light to the black screw on the 3way switch. Now connect the red wire and black wire from the wire you ran between the switches to the other 2 screws on the switch. It does not matter which you connect to which screws. Connect the ground wire and put that switch in the wall with the cover on it. Now move the the other 3way switch with the power wire. Again connect all the whites together and shove them back in the box. Connect the black wire from the power source to the black screw on the switch. Now connect the other 2 wires left, black & red to the other 2 screws that are left. Again it matters not which wire you connect to which 2 screws that are left. Connect your ground wire and put the switch in the wall a cover on. At the light connect the black to black and white to white. Connect the ground wire to the green or ground wire on the light. You are done.
This requires a 3way switch at each of the 2 locations you want to use to control the light. You will need to run power to one of the switch locations and then run a wire to the light from the other switch location. Run a 12/3 or 14/3 wire from switch to switch. Be sure and use the same size wire you use to supply power and run from the switch to the light. Do not mix wire sizes. If the circuit is on a 15 amp breaker then use 14/2 wire, and if it is on a 20 amp circuit use 12/2 wire. Now you have power at one of the 3way switches. A wire going to the light at the other switch, and a 12/3 or 14/3 wire running between the 2 switches. Starting at the switch with the power supply input connect all the white wires together under a wire nut and push that back in the box. Connect the ground wires together and connect that to the green ground screw on the 3way switch. Use a jumper wire if necessary. Look on the switch and you will see 3 screws. One is black and the other 2 are silver. Connect the black power wire to the black screw. Connect the red and black wires, which are called travelers, to the other 2 silver screws. Does not matter which wires you connect to which screws. Remember you are supplying power to this switch and not to the other switch. The black wire you connect to the black screw is the wire coming from the power wire you brought into the switch box, and not the 12/3 or 14/3 wire you ran between the switches. Now move to the other 3way switch. Connect all whites together and push them back into the box. Connect the grounds together and then connect them to the green ground screw on the switch. Now connect the black wire that is going up to the light to the black screw on the switch. Connect the red and black traveler wires to the 2 remaining screws. Once you install the light, black to black and white to white, ground to ground. Turn on the power and if you followed these directions to the letter you can turn on/off the light from 2 locations.
You only have to break the black wire because it is the hot wire.
You never switch a neutral wire, only hots. hooking both hot and neutral to the same switch will result in a short when the swith is turned on.
you can only have one dimmer, the other switch needs to be not a dimmer. the green wire is ground, it connects to a bare copper wire found in the box, or to the box itself, if the box is metal. the black wire is"common" it either connects to the wire found in the box that has power in it or to the black wire that goes to the light. the 2 red wires are"travelers" they connect to the wires found in the box that go from switch to switch. if you don't know how to check which wire does what( continuity), it is possible to keep changinging the connections until the switch works. you will want to do this with a conventional switch, and install the dimmer afer you identify what wires are travelers and wich are common. you will destroy a dimmer switch by searching for the right connection. once you have identified the common wires, it will be on the black screw of a 3way switch; you can put that wire on the black wire of the dimmer. one red goes on one traveler, the other on another traveler. there might be a white wire in the box, if it is connected to other white wires and not to the switch, leave it alone. if a single white wire is connected to old switch, it may be a traveler.you will connect a red dimmer wire to this. opening the other switch location will show you if the white wire is used as a traveler.the black wire has to be either power coming in, or the wire going to the light. the reds are just connecting the 2 switches.
Piggyback off the box for the existing light. Run a wire from the existing junction box to a new junction box (which is placed wherever you want the new fixture). Then, in the existing box, connect the wire coming from the switch, the wire for the existing fixture, and the wire for the new fixture together using wire nuts. Wire up the new fixture, and presto, you have two fixtures on a switch where there was only one before.
Yes just determine which wire going into the switch is the hot power wire which will be black. Just send power from that black wire to the outlet.