hello citypat. i just went through the same thing that wannabe suggests. power was going to the little posts inside the bulb socket, but the bulb would not light because the connection where the bracket was bolted to the pickup box was rusty and painted![not grounded properly] and the connection between the bracket and the light housing was rusty and painted![ not grounded properly]. both areas needed to be cleaned to the bare metal before the housing and the light socket was properly grounded. and now the bulb will light, but i am still going to run another ground wire from the frame to the light housing to prevent future troubles. i hope that after you get the socket and housing working properly that you can figure out which hot wire goes where. i assume you are using a two wire socket and a dual filament bulb on each side. expose the two wires coming from the socket. with the light switch in the parking light position, find the wire coming from the front that is hot, and connect it to one of the wires from the socket. one of the filaments should light up.[one is dim, the other is bright]. connect this hot wire to the one that lights the dim filament.that should take care of your parking/running light on that side. now do the same routine on the directional/brake light.turn off the parking lights. turn on the directional switch[on the side of the car you are working] or the brake switch and find the hot wire coming from the front. connect that wire to the other wire coming from the socket. the directional/brake light should work and light the bright filament of the bulb. i hope this helps. good luck.
