Light on....light off.........it's driving me up the wall.

I had HID fitted to my standard crystal bug eye head lights and for some reason the drivers side light has a mind of it's own.....
Sometimes it comes on, sometimes it decides it's had enough.
Only recently when it's been on it starts flickering........then goes off......

I was told it was the stalk? but now i'm thinking more like a bad earth of some sort?

Any ideas please?

 

Mine did this once I found that the light connectors were loose after it came back from the subaru garage, once tightened up they were fine,