Hi,

I have spent some time figuring out light switch.
most of its contacts are directly connect signal pins to ground, fog light contacts are trickier. they are relayed - they use voltage from pin A4 (Term.15) which is a switchable power and this relay if activated drops voltage on pin A5 (fog light) to 0.

So, what to do with this knowledge i have not decided yet. simplest way would be to force open light switch and put a short circuit for that relay that activates fog lights - this way any time you turn your ignition on it would light up fogs. i just really do not want to put any more circuits there to the battery and extra relays.
Or you can connect home link wire to fog light wire - that way it would be working in 'dual mode' and cause fog ligts to light up, hopefully, with ignition on.
Or it is possible to put an external relay that would use voltage on pin A4 to short pin A5 to pin A6 (Term.31 - ground).

also, sun sensor we have sits on a blue wire that comes to pin 1 on Y connector of CU climatronic (pin B8). theoretically it can be used together with pin A4 of light switch (ignition) to trigger low highbeams relay to automate lights function. but it depends if they amplify sun sensor signal or feed it as it is, as analog voltage from a diod.

not sure where to fit all that music, front panel does not have much space in it. plus it requires plenty of work in the crippled position...

PS. just tested, it, A5 directly shortened to ground activates fog lights only after ignition turns on, ECU is smart enough to do it. so it is very interesting question why factory installed a relay driven by ignition voltage on pin A4 if it is apparently not needed. they have 'automatic lights' ('home' position), all those pins have car logical '1' - 11v and to 'activate' function it gets connected to ground. i wonder what battery discharge it causes, if any, i was not able to measure anything. still they got a relay for fogs, and only for fogs, strange.

Looks like one can just safely solder 'home' yellow/red and 'fog light' yellow/white wires together in the light switch wires pack and then in 'home' position left 'on' you will have fog lights working while driving.

 

i would like to have fogs on like a 997.2 and bought a detane module but didnot install it because i have a 997.2 bumper and lights on my cr(2006) and do not wish to remove bumper to access wiring. i considered trying to catch the wires behind the rt head light . then i heard if you put the batttery mainainer on it will cause this to flicker as it charges. i found that the 997.2 headlight switch while looking the same is a different part # , do you think that is the way they get the fogs on when ithe ignition is on? does the automatic light work like other cars when the car is in the dark the lights go on? alot of questions i know but you wem to have electrial knowledge. mike 206 920 0332

 

'automatic' light is just a 'home' position at light switch. in 'home' position it only lights up fog lights when you switch ignition off and then turns it off.

all light switch does is connecting signal wires to the ground. so what i see - it you 'hack' wires a bit there and make pin A5 connected to ground - car will turn on fog lights when you turn ignition on.

simplest way to get A5 conencted to ground and make it switchable is imho to solder it (or tap it) together with pin A2. this way when you turn light switch into 'home' position it will turn fog lights work with no other ligts on.

 

where did you get the wiring diagram for the 997.1 headlight switch. do you have one for the 997.2 headlight switch? thanks in advance mike

 

Good afternoon gentlemen,

There is an automatic headlight solution for 911 997, Boxster and Cayman 987 and CAYENNE 955 and 957.

I run it on my 997 TT; installed in minutes and almost invisible.
No need to change the original switch

its called PALS, check autolightsystems com website.

Cheers

 

$799 for that product is ridiculous