I got in my truck the other day and went to turn the lights on at night and they all of a sudden just did not go in. The night before they were working fine and the high beams still are working but the headlights will not go on. I checked the fuses and they were all fine. I am thinking it could possibly be a relay but I am not sure how to check that. Please help me and let me know if anyone has an idea about what this may be or what I could do. Thanks...