1995 Buick Century 1995 Buick Century Tail Lights

OK, so my girlfriend got rear ended recently and had to have a used tail light bar put on because apparently they dont make new ones anymore. A couple days ago, her tail lights stopped working. I say take it back to the shop but her dad blew that all to hell by telling the shop that the problem was under the dash (i doubt it). I haven't had a chance to tear into it yet, but I cannot find a wiring digram for the tail lights anywhere. Supposedly the fuses are good but im going to double check. Also, its just the tail lights, brake lights and blinkers still work fine. Any help or schematics would be much appreciated