I have 2 light bars on my plate holder. The first is very simple, it hooks up to my running lights and to the brake light to light up whenever the brake light comes on. The second is pretty much the same but goes to the turn signals as well and when the brake light comes on it flashes very quickly and then slows down gradually until resting at solid red. It's all wired as per instructions, and works perfectly as long as the harness isn't plugged in to the stock bulbs. Electrically, there's no difference I can see, but then I'm not an electrician, anyone have any ideas on this little conundrum?