Auto lights - are my eyes deceiving me?

[Watts]

Morning all.

In the last couple of days my lights are coming on when it's not particularly dark, late afternoon so the sun is low and the shadows long, but when exiting into normal light conditions they are taking ages to go off again. I'm sure they weren't like that before and at the time no other cars had their lights on. Also yesterday when I was out in the rain, the wipers seemed a bit slow at coming on too although tbh, they were better for it as they usually come off intermittent far too early.

So, is there a fault with the sensors? The lights are set in the menus to 'medium' delay and I've not changed that.

Cheers

[clubsport]

Hi Watts, although they control lights, wipers and climate temperature the sensor is one unit in front of the rear view mirror. Any of the 3 functions that misbehave, results in changing the whole unit.
( I did this on a previous Golf).

For the lights, the default setting for a broken sensor is for the lights to be on full time when the switch is set to auto. A working light sensor effectively turns the lights off in daylight.

Also coming home/ leaving functions don't work if sesnor has problems, check that?

When I had the issue on a previous Golf, it did occasionally inform me on the dash of issues with the light sensor, until you get that, hopefully there is nothing to worry about.

One thing to consider, if it does turn out to be a problem when they repaired your roof, did this involve removing the windscreen, or more likely the rear view mirror in the process?

[Watts]

Hi Watts, although they control lights, wipers and climate temperature the sensor is one unit in front of the rear view mirror. Any of the 3 functions that misbehave, results in changing the whole unit.
( I did this on a previous Golf).

For the lights, the default setting for a broken sensor is for the lights to be on full time when the switch is set to auto. A working light sensor effectively turns the lights off in daylight.

Also coming home/ leaving functions don't work if sesnor has problems, check that?

When I had the issue on a previous Golf, it did occasionally inform me on the dash of issues with the light sensor, until you get that, hopefully there is nothing to worry about.

One thing to consider, if it does turn out to be a problem when they repaired your roof, did this involve removing the windscreen, or more likely the rear view mirror in the process?

Thanks for the comprehensive reply

I don't think it relates to the roof repair as that was over a year ago and it's only been the last few days. It might just be the lower light in the evenings but it didn't seem right. There have been no warnings so as I still have plenty of warranty left I'll see how it goes. It would be better if it completely failed, at least then there would be no argument!

[clubsport]

From what you are saying it sounds ok, as I mentioned the default for the lights is on with the sensor turning them off in bright conditions. it makes sense for the lights to be on for longer  as there is less light and darker evenings.

[Talk-torque]

I’ve wondered about variations in the ambient light levels, when the headlights come on, before and came to the conclusion that the switching seems to depend on the contrast between the forward view of the sensor and the rearward view inside the car. I have no clue as to whether there is any fact in this, it’s just my perception of how it seems to vary.

[Watts]

I’ve wondered about variations in the ambient light levels, when the headlights come on, before and came to the conclusion that the switching seems to depend on the contrast between the forward view of the sensor and the rearward view inside the car. I have no clue as to whether there is any fact in this, it’s just my perception of how it seems to vary.

The sensor is forward facing though surely?

When I was out today all seemed to work well enough and they switched off promptly on exiting a darker area.

[Will2018]

You are correct in saying that the auto lights are able to detect when the sun is low and behind the car.

A perfect example of why it’s useful is when travelling West to East on the motorway when the sun is low. Your lights being on allows your car to be better seen by cars in front against the bright sun in their rear view mirrors.

Lots of people don’t understand and I’ve seen many confused people asking where their light are on when it’s still light.

Mine kick around 4pm on a sunny day on a small bit of my motorway commute which goes East to West. As soon as I’m facing North again they go off until around 5.30 when light levels drop properly. 

[Philip]

Not sure if this is relevant to the scenario you are describing Watts but my impression is that there is something built in to the algo's that control the lights which takes in to account if the wipers are / have been active. My lights will come on earlier than usual and stay on for longer when the wipers are active (as in they are in auto rain sense mode, have been working and haven't fully parked again) regardless of ambient light levels.

[Watts]

You are correct in saying that the auto lights are able to detect when the sun is low and behind the car.

A perfect example of why it’s useful is when travelling West to East on the motorway when the sun is low. Your lights being on allows your car to be better seen by cars in front against the bright sun in their rear view mirrors.

Lots of people don’t understand and I’ve seen many confused people asking where their light are on when it’s still light.

Mine kick around 4pm on a sunny day on a small bit of my motorway commute which goes East to West. As soon as I’m facing North again they go off until around 5.30 when light levels drop properly.

That would fit other than I've never noticed it before. Thanks for the explanation.

Not sure if this is relevant to the scenario you are describing Watts but my impression is that there is something built in to the algo's that control the lights which takes in to account if the wipers are / have been active. My lights will come on earlier than usual and stay on for longer when the wipers are active (as in they are in auto rain sense mode, have been working and haven't fully parked again) regardless of ambient light levels.

Cheers, worth bearing in mind however it was bright sun and no wipers when I noticed what was going on.

[Watts]

Thanks everyone for as usual all the helpful comments