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.
Remove the old single pole switch. Connect the green dimmer wire to the ground wire. Now connect the black dimmer wire to the black wire that is the hot wire (wire carrying the electrical current into the box). Connect the red dimmer wire to the other black wire.
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.
Sounds like you are are installing a single pole switch (your load is controlled from one location only). If your existing switch is hooked up to a black and a white wire you are dealing with a switch loop and that white wire is being used as a hot wire. Make sure the circuit breaker is off of course, and hook up the black wires on your dimmer to the existing black and white wires on the original switch (polarity doesnt matter here) the green wire on the dimmer is a ground and should be hooked to a bare copper wire or green wire in the box if it is there.
Connect the black wire to the incoming hot wire and the red wire to the out going load.
If you have one wire into your switch box for your light. this is called a switch leg, the dimmer should be wired across the black and white wire wires.
12v switched source. such as headlight switch or dimmer on the dash.
you will need 2-3way switch and 2-4way switch
you can find it in alldata
1 is for the positive (+) source and 1 for the negative (-) source
No, the dimmer switch needs its own individual circuit power supply to feed the fixtures connected to it. The black of the second dimmer switch can not be connected to the red wire of the first dimmer switch. Now if you are talking about using a common "hot" to feed two dimmer switches then this can be done. The neutrals will be common also. So what you should have is two black wires connected together with the incoming "hot". Two neutrals connected together with the incoming white. The red from each dimmer is then connected to its own individual fixture load.