Faulty headlight

[David Fisher]

I recently replaced my xenon bulbs in my 62 plate a4 after one stopped working.After replacing them I noticed that one of them stays on full beam  when at the night time setting and when I flick the stock up to full the other one becomes brighter but when I flick back down the faulty one remains on full.So basically one of my headlights is constantly on its brightest setting.I swapped the bulbs over to make sure it wasn't a fault with the bulb,but the same thing happens.If anyone has any experience of this fault or can help in any way with any information it would be greatly appreciated.Thanks in advance.

[James]

Hi David are they bi xenon or do you have a separate halogen high beam bulb?