Automatic light sensor for low beams - have anyone done it before?

[utkinpol]

Hi,

I am trying to write up schematics for making DIY module to put into my 997 C2 so car could turn on/off low beams automatically as any other modern cars do.

First idea was to cut into wires from light switch but after studying wiring diagram I also see some other input named 'switch automatic light' that goes to contact A33 in onboard comp. Does anybody know what is it for?

on light switch it sits on contact A2. Or is it that 'Home' selector mode? I did not try to take light selector off so I did not check yet what is what. Just trying to do preliminary design so far and then will try to find suitable sensor kit from other brands.

Have anyone tried to do such a project before? I drive in tunnels quite often here in MA so it finally annoyed me for car not to be smart enough to turn on lights when it`s dark. I plan to put it on 'Home' selector dial so it could just sit there indefinitely - this 'Home' mode is useless anyway.

[utkinpol]

I keep studing wiring diagrams and got very confused now - apparently every Porsche does have sun sensor already.

It is shown on Sheet 3 CU Rear diagram and it apparently connected to CU Climatronic, contact B8.

But I cannot find any day/night output from none of CUs. Perhaps I can try to hook a relay into sensor output directly... Hmm...

[PAULSPEED]

Why not find the trigger mechanism for the mirrors. My

car came with self-dimming mirrors.

Paul

[utkinpol]

Why not find the trigger mechanism for the mirrors. My

car came with self-dimming mirrors.

Paul

Hmm... Not quite positive about it but I believe mirror has its own sensor and it is not day/night type.

I am actually almost sure mirror is pretty self-sufficient and only takes power from a car. There is no sensor output there.

the only usable one is stock sun sensor. I just really want to get to it somehow as to install one more sensor will be a tricky job, not to mention all aftermarket ones are quite ugly from what I`ve seen. Challenge now is to find where does that wiring from stock sensor go and measure it when car is on.

If it delivers logical 12v - it can be probably used directly on a relay. But I suspect it may not be so easy as usually such sensors deliver much lower voltage and it has to be amplified somewhere.

I really cannot comprehend the logic of Porsche to actually put **** sensor in but not to wire it into beam light system.

[RFM]

Some (ROW) Cayenne versions have automatic on/off low beams, the sensor is located behind the rear view mirror, on the same spot as 996/997 rain sensor, the Cayenne sensor is double functional light/dark and rain, cause they command the wiper speed also, Cayenne have also a different light switch with an extra possition named "AUTO".

Perhaps you can have a larger view on parts, wiring and how to do, if you can arrange a Cayenne electric diagram.

[dphatch]

Hi,

"I drive in tunnels quite often here in MA so it finally annoyed me for car not to be smart enough to turn on lights when it`s dark. I plan to put it on 'Home' selector dial so it could just sit there indefinitely - this 'Home' mode is useless anyway."

Don't your DT running lights serve your purpose for driving through the tunnel or are wanting to see you gauges ? In any event, this would be a great upgrade for use when it's too dark to see your gauges at night, if you can figure it out I'd love to do it myself. Have often wondered why Porsche didn't add this capability to the system from the get go as most everything necessary too make it happen is already in the car an adding the proper relay at the factory would be a cheap and easy mod when building the car. Doing it after the fact won't be I'm afraid.

[dphatch]

OK. Did Google search and found a goodly number of add on kits to make this happen. ( Haven't found a Porsche specific solution yet ) Will do some further research but it appears this a "doable" mod for not a lot of cash or a lot of "electrical engineering" expertise .

On second thought, having done a little more research.... :o This may not be as simple as I first suggested. Looks like the key maybe the rain sensor but on one of the BMW forums a member tried it and wound up with some additional issues that were worse than the the cure for the original project. And something was mentioned about a wiring harness..... That means maybe an electrical engineer will be required after all.:rolleyes: All the other aftermarket solutions require cutting up wires and attaching sensors to the dash, and generally mucking up stuff that the Porsche gods don't want you to muck up. Maybe trading the car in for a new one whenever they add this feature would be easier. :D

Edited January 1, 2010 by dphatch

[zeltron75]

Resurrecting an old post on this topic, have a look at https://autolightsystems.com which works on the original switch "home" or "low beam" position of any 997 1 and 2, Boxster Cayman 987 1 and 2, Cayenne 955 and 957 and automatically switches headlights according to day/night and speed

Edited January 7, 2021 by zeltron75
adding infos and avoiding duplicates in other sections