nean intallation help

hi
read on this site what to do, and have a basic idea. i tapped into what i thought was the lights cable ( the wire under the dash - the ran that into the light. also put one of the wires onto a scew inb the car ( for the earth one) but the light wouild not switch on!! so i figured i missed the car light wire, so i tried another...and another...and another!!! but all had no effect! i dont think it is the lights that dont work, cause both of them are brand new! but when i bought them, they had a cig lighter attached to them. i discovered my crap car dont have a lighter, so i just cut the adaptor off. is it concievable that there was something in that adaptor that i needed? help would be most appricieated!!

u should still be able to do it that way just wire it to power with a switch there or something..

cheers. will give it another go! thanks!