sooo if I want to hook it up to a switch, I just take the illumination wire and look that to the positive to the switch? and then ground it? please explain
The illumination wire is normally connected to a wire in the car that becomes +12v when the headlights are turned on.
If you want to do this manually with a switch, then connect a +12v source wire to one side of a switch. Then connect the other side of the switch to the D3's illumination wire. When the switch is closed, the D3 will dim. When the switch is open, the D3 will be in full daytime mode.
Right now, mine is connecte