There are no exact instructions on how to wire this up, however they do supply schematics. I had to purchase extra wire to link the front and the back lights on both sides. But that’s not my main issue. After I got it all wired up I went to power the yellow lights I installed and found that 3 out of the 4 were broken. I didn’t notice the cracks in the plastic when I was installing them and upon further inspection after trying to power them up I saw they were cracked. The 4 red lights are working. And I haven’t had an issue with the relay or switch this far.If you do purchase these check your lights before install to make sure they work!