If you checked the fuses and everything is good there, it's most likely your turn signal stalk/headlight switch. They are fairly inexpensive (nearly $60) and can be ordered from Autozone website. However, there could be another issue going on here that is very similar. It was also the problem I had. I replaced the sealed beam headlights with a H4 halogen bulb housings. The H4 bulbs I used were high-power, IPF Fatboys and pretty much melted my headlight connector where it connects to the switch in the steering column. They say to replace the headlight harnesses at the headlights when you do a H4 conversion but there is nothing to beef up the wiring harness on the steering column end. Hence my no low-beam troubles.