Need electrical help - turn signal / park lamp

[dmjlambert]

I had a license plate light assembly that would not conduct from the socket to the housing to the bumper no matter what I tried. I even cleaned up and could see with my own eyes bare metal surfaces touching together, and it would not work. I ended up running a wire from the bulb socket to the bumper and it worked and got me through inspection. I eventually replaced the assembly. Sometimes I don't know what the deal is with grounds, and they are a mystery, but I know they are important.