I have a '96 Discovery and suddenly both headlights stopped working. I tried replacing the bulbs and that's not it. The fuses are all fine. The high beams work but only when the control switch is held in. Anyone have any idea what might be wrong???

 

If it's common to both lights, look to something common to both, the switch, the relay, etc. Sounds like the switch to me since you have to hold it to get the high beams to work.