Driving about on the continent a few weeks ago (weather beautiful, temps not below 20C anywhere, on the 18th Oct and was sitting outside having dinner at 9pm and noticing it was 28 in Port Vendre,) so pretty much sunny where we where. I usually leave the tunnel lights on all the time and rely on the tech to shut them down as necessary. However I was noticing that even in the bright sunshine the dips would stay on most of the time, and even when they went off, would come on again at the slightest provcation. Is this as it should be? Am I missunderstanding how they work? Or is there some way of calibrating them to be more "off"? Or could something be broken?

Thanks

Two views on this...

1) A low bright sun can actually reduce visibility. Hence the sensor is able to detect the level of light and turn on dipped headlights even during the day.

2) The bright summer sun confuses the sensor, hence dipped lights coming on unexpectedly.

It is also worth remembering that cruising at a certain speed (80mph I think?) also activates the tunnel lights.

I'm sure I've seen a similar thread on one of the Golf forums. IIRC it is also something about the amount of contrast i.e. rapidly moving from dark to light. If the ambient light is a bit "flat" then as Silver1011 says it will continue to run on dipped even during the day.

SWMBO has also just reminded me that her old C3 Picasso was the same and she was told something similar by the Citroen master tech.

Thanks for the replies guys. The situations 1 and 3 Silver1011 postulated didn't apply in the situation I was in, the 2nd makes the whole thing a bit pointless, no? It was bright but mainly from the side. And it seems to have changed for the "worse" over time. Back to the old hand job.