i bought a cattleman rear bumper replacement and im trying to figure out how to wire the new license plate lights up, when i cut off the the existing bulb and clip there was 2 wires, one was brown which was the hot wire and one was black which im guessing is the neutral. coming out of the new lights there is only 1 wire, my first attempt to wire the light up, i put all the wires together and i blew a fuse, i currently have just the hot wire connected but when i turn on the switch there is no illumination. any ideas??

 

Check the new bulb configuration, it sounds like it is using the bumper to ground the other side of the bulb ( DC equivalent of AC Neutral aka return side of the circuit ).

If the bulb is grounded to the bumper, make sure the bumper is grounded correctly. If it has all the mounting holes nicely powder coated, then that is the problem.