Depends on how the headlight assembly is set up and what you want the halos to come on with. The sets I've seen have a resistor pack encased in a black epoxy cube with 2 wires coming out and almost seem to be set up for a/c rather than d/c with a positive and negative, unless of course you have 2 different color wires and one of those colors is black. The last 3 sets I've come across just have 2 same colored wires and either wire can be tied in to the positive and negative of whatever light you want the halos to come on with. Example, if you want them to come on with the low beams, simply tap one of the halo wires into the negative black wire and the other halo wire into the positive, tape it up nice and pretty and done. Pretty simple, resistor pack throws people off tho.