Impressive Dimmer Switch 2 Black Wires
Turn off power and connect the corresponding wires from the junction box with the insteon wall switch an cap them with wire nuts.
Dimmer switch 2 black wires. Separate the black wires and cap them with wire nuts. The black line wire connects to the common terminal of the 3 way dimmer. A two way dimmer switch has three wires coming out of the back.
The simple answer for a typical two way dimmer switch is black on the dimmer goes to the black wire in the wall the other black on the dimmer goes to the white wire in the wall and the green wire on the dimmer goes to the bare copper wire in the wall. This is your line wire. In the diagram below a 2 wire nm cable supplies power from the panel to the dimmer box.
I m installing dimmer switches one i already had and a new one i just bought. A 3 wire nm connects the travelers of the dimmer to the travelers of the 3 way switch. Only one of those black wires is hot when the two black wires are connected via a switch then it sends electricity to your light.
Install insteon wall switch attach the wall plate and turn on power. The junction box has 3 sets of wires coming into it. One of those black wires should be white painted black it is.
Traveler wires are interchangeable on each switch.