Adding auto lights with factory light sensor

[Benjamin2000]

Hi everyone,

I have a 2018 Seat Leon MK3 ST (estate), Full-LED version. Unfortunately, my headlight switch doesn't have the AUTO position, so I don’t have automatic headlights. However, there is a sensor mounted behind the rearview mirror on the windshield – possibly a rain/light sensor. Also, in the infotainment settings, the “coming home/leaving home” light option is visible, but it doesn’t seem to work.

Out of curiosity, I tested whether the light sensor might be active. At night, I manually changed the system clock to daytime – but the built-in navigation remained in dark mode. This makes me think the car does in fact measure light levels outside, regardless of the set time, possibly using a light sensor that's already installed.

That makes me wonder if the car is already partially prepped for automatic headlights – maybe all it needs is a switch with the AUTO position and some coding. Has anyone here successfully added the AUTO headlight function to a similar model? Is there a proven method or retrofit kit that works with the Leon MK3 ST? I’ve attached a couple of photos in case that helps identify what’s already there.

Thanks in advance for any advice!

Cheers!

 

[East Yorkshire Retrofits]

It’ll have a humidity sensor installed. Replace with a rain light humidity sensor and replace the switch, then make the configuration changes

This has been covered loads of times on here and there’s multiple guides to follow

 

[LeylandVCDS]

Personally I find vehicles on a motorway with the lights constantly switching on and off as they go under bridges, is both distracting and annoying. It's sometimes a natural reaction to ease off or brake when a vehicle in front of you suddenly shows red lights at the back - yes I know they are not as bright as brake lights, but they are red lights none the less. It's not a function that's needed, especially these days with everything having day running lights anyway.
I still can't get my head around who thought it was a good idea for DRLs to be "generally" front only. If there ever was a situation where lights are needed, rears are surely just as important as fronts, and the number of vehicles driving around illegally with no rear lights on at all in poor visibility in dark or in the wet is truly mind boggling. And equally mind boggling is the sheer number of folk who open admit they don't actually know their DRLs are front only, and hence rely on them in the said poor lighting or visibility, believing the rear of their car is adequately (and legally) lit up.
First things I did with both my previous and current Leons was activate rear tail lights with the DRLs - and deactivate the auto lights