need electrical help

i recently bought one of those license plate frames that has a light in it. well the light is only a one wire hook up,and the light is self grounding. well i have a wire running from my light switch back to my light and i get power at the terminal where the light sits (i do not know the volts all i got is a test light) but the bulb does not light up. i tried to replace the bulb thinking is was blowen but the new bulb does not light up either. any help would be greatly appreciated.

I'll bet you dont have a good ground. Try a short length of wire to go from the frame or bumper to the bulb holder or any other metal part of the license plate holder

hey thanks bro ya i kinda feel like a dumbass i thought of that right after i wrote the message...it works now by the way thanks again