It would have been helpful if they'd come with some instructions. i'd thought 12V DC didn't care about - %26 , but these LEDs do. White wire to Black to work in this case. They've got 3-way switches! Off, Both sides on, and one-side-only on. I thought I had a bad connection on one side, but it was a "feature". The light covers are hinged on the ends, and you pry them out from the middle. That's different from other brands that slide out. They're bright and a cold blue-white. I'm getting some yellow, transparent foil to cut down on the blue light.