Help... car just failed it's MOT on both head lights not working and the headlamp relay is buzzing... tried changing it to spare and it spare buzzes!
Any idea of what can cause this?

Poor conection on the actuator side of the relay, check the connectons feeds etc to pins 85 & 86

Thanks... where would the most likely are for the poor connection be? Around the steering wheel or on the relay box? If I wiggle the relay it stops and the lights come on (so I guess that gives me a clue :-)

Yes, sounds like the contacts in the relay socket need tightening up, there was a thread last week or so about somone doing the same thing.