You will need to hook the Black wire to the Line in which should be the Black. The white wire will hook into the white wires. The whites are probably hooked together with a wire nut. Just add the Switchlinc’s white wire to them. The Yellow wire is the input for slave switches. If not using, cap it with a wire nut. Now comes the ground, if your switches do not have a ground, look into the back box and see if there are a few bare copper wires. These are the grounds and you will need to hook up the Switchlinc’s bare wire to them. If your house doesn’t have a ground wire, try it without if but you may need a ground. Some of the nicer dimmers like Switchlinc require a ground where as the cheaper ones work fine with out.

Chris Couture