headlight problems

so after i install my manual pedals, i go to take my friend home and my headlights don't work. the highbeams do. everything works BUT the headlights. the wiring diagram i have suggests one wire in particular, which i'll check out tomorrow. there's also a brown box under the dash, right next to the steering column, that got cracked when i was wrestling with the pedals. could that have anything to do with it? any help, please...