Testing headlight unit


Registered User
Hi All,

My girlfriend's A1 (S-Line, xenons, MY15) has been throwing an intermittent fault with the near side dipped beam. The light occasionally works, and occasionally doesn't. Cycling the ignition and flicking the lights on/off a few times can sometimes get it working again, but not always, and it isn't improving over time.

We've tried replacing both the bulb and the ballast, but the problem persists, and both dealers and independents have no suggestions short of replacing the entire unit (£350+ second hand, north of £600 new).

To test things a bit more thoroughly, I was considering plugging the left headlight into the right socket (and vice versa) to see if it's a fuse/control issue, or an issue with the headlight unit. I'll clarify that I don't mean swapping the bulbs, I mean swapping the entire headlight unit to test them.

Does anyone know if it would be safe to plug the headlight units into the opposite sides? I'm unsure as to which pins are live etc., and whether plugging them into the wrong side would mess something up.

Any help would be grand, cheers.