1984 Cadillac EL Dorado headlights not working

My headlights didnt turn on the other night.I have the twiilight sentineal. They dont turn on even with that off and pullling out the manual knob. Ive heard of a relay swith and a fuse. Looked in the fuses under the lefthand side of the dash. Cant find anything there. Oh the brights also turn on by the way. Not sure what to do short of take it to cadillac but I reallly dont want to if its just a fuse! Can anyone help? Also is there more than one fuse box? Thank you!