94 seville headlights

help I have no lights, my daytime running lights work but soon as it gets dark when my lights come on nothing ,running lights work but no headlights , no low beam or highs . did replace the high and low beam diimmer switch but that wasnt it . any ideas I was thinking head light switch but cost over 300 new and havent found in the wreckers yet and dont want to replace if thats not it