hey, i recently removed my Rear bumper, i simply just unplugged the bulbs from the bumper, by unplug i meen, just took them out of the small hole in the bumper.... anyways... i mounted my license plate and lights and now the lights dont seem to work... and idk why, i didnt unplug any wires or cut nething ... unles they never worked in the first place?...

 

Do you have a test light or a volt/ohm meter.
If you do just check for power to the socket, if you have an ohmmeter, you can also check for continuity on the ground side to the frame.