fuel pump

i have a 1991 passat GL factory engine, no mods. i just changed my fuse box out for one i got from the junk yard, and all the connections seem to be working right however, my fuel pump doesnt seem to be working and it was working just fine before, i have checked all my fuses and all are operating, but relays arent exactly my strong point. In order to be the cprrect relay, does it have to fill all the prongs? Could i have gotten the wrong fuse box if all my other connections are working right? Any help is greatly appreciated