sorry for not replying earlier chaps, and I'm no expert sam....., an ex is a has been, and a spurt is a drip under pressure !!!, and I'm not even that good.
Some stupid so and so went and hit my prized beamer, driving daddys car and doesnt have any insurance, daddy has decided it isnt his problem, son doesnt have any money, (you should see the house they live in, with its two detached double garages etc), so I'm walking now.
I'm sorry that didnt solve your problem sam, it sorted mine, if your over this way you can borrow the control box from mine, it isnt going to need it for a while if ever again.
What seems different about your problem is you seem to be saying it is only 1 light going out, mine was both dip lights, if its only one its much more likely just to be a wire of bulb holder, my offside rear buld holder used to like doing that until I threatened it with a pair of pliers.
Can you let me know if you mean 1 or both lights?