Hi all, This is my first post. I have a 2006 GMC Envoy. My low beams quit working, but not all the time. I'd say about 80% of the time they don't work. Since they work occasionally, the bulbs are not burnt out. We did relpace the relay switch and they still don't work most of the time. We did not check the fuses, but again, if the work occasionally, would it be the fuses??