1998 Nissan Truck head light not working

1998 Nissan 4x4 Hardbody mileage: 120,000. I just bought this truck as a project, and I have every thing working great with the exception of the driver's headlight. It works on high, but not on low. I've replaced the bulb and fuses with a known good ones. It has 12 vdc while unplugged, but with a load, nothing. I've looked in the Haynes manual for a diagram, but there is not an accurate one for that year. Any Ideas? Any help would be appreciated.