How do I wire a 2 way dimmer? There are 2 black and 1 red wire coming from bos. White one is already attach in back of box. Switch has 2 black and 1 green wire (ground).
Look inside the box, there are probably two cables. One of the cable will be a three wire with a white, black and a red, the other will be a 2 wire with black and white. The black wire from the two wire cable most likely needs to be connected to the red wire of the dimmer then connect one of the remaining wires of the dimmer to the red of the three wire cable and the other black from the dimmer to the black of the three wire cable.
What are you trying to accomplish.
A 3-way switch or dimmer allows you to control the light from a 2nd location.
Do you have a 2nd location with a switch that controls this?
If the current switch only has 2 connections (plus ground) then it is not part of a 3-way circuit.
My guess is that this controls a ceiling box and that it is prewired for a fan?
If so is a fan installed?
If not and you want ot install a basic dimmer (ie; not 3-way) just connect it to the same set of wires.
A 3-way switch or dimmer allows you to control the light from a 2nd location.
Do you have a 2nd location with a switch that controls this?
If the current switch only has 2 connections (plus ground) then it is not part of a 3-way circuit.
My guess is that this controls a ceiling box and that it is prewired for a fan?
If so is a fan installed?
If not and you want ot install a basic dimmer (ie; not 3-way) just connect it to the same set of wires.