Edgy01

I think I would be a little leery of cross tying a couple of wires that way. I like being able to go backwards.

utkinpol

huh? meaning?
it is all digital. all switch does is a direct connection of a signal pin to a ground ('0') or to a source of switchable power ('1').

and of course anybody who starts slicing wires on a $100k car is on his own. i just did show you where to look. all i can say for sure - 'home' A2 pin gets connected to ground directly. pin A5 for fogs sits on a relay but when fogs are on voltage on the pin is 0. when you test it with ignition off there is a resistance between ground and pin A5 even if switch is on fogs and as i did not want to take light switch apart i did not dig there to see what kind of a relay is in there. so far i have it this way for a several days and ECU seems to be alive so i want to think it is safe enough. but no guarantees.

Musclehedz101

utkinpol, any tips on how to remove the switch from the dash without "injury"? It seems pretty secure in there and could see how to remove.

TIA

Musclehedz101

Disregard, prior request. Did a YouTube search and found this video on how to remove switch.
Procedure to remove light switch:
1) Switch dial to “Home” position
2) Press on the headlight switch so that it moves inwards, (maintain pressure inward).
3) While pressing firmly on the switch turn the switch clockwise.
4) Pull firmly on the switch and it will slide out.

Once I had switch out, it took me 5min. to complete the process and 5min just enjoying and playing with it! WoooHooo! Love it!

Thank you, utkinpol for sharing and posting!

Regards

Fiftybe

Many Many thanx ! I had already installed the generation 2 DRL/fog lights on my turbo, but no way to get them to work ! Thanks to you everything now works perfectly, and as you said, done in under a minute!

juniormarbles

Utkinpol: Did you disconnect the battery during installation? Or will it suffice to keep the keys out of the ignition and the light switch in "off" during installation?

My other question: I will install this jumper in a 2006/7 Cayman S. Do I assume correctly that the wiring for lighting is the same (at least my light switch shows the same functions as on a 997/1) ?

juniormarbles

I precisely followed Utkinpol's instructions of installing the wire bridge. I had no problems with the mod- it functioned as described.

But after a few days in the garage, my battery (flawless performance until now, D.O.M. 03/11) was down to 2.5VDC. Assuming I had left something running that caused the battery to run down, I recharged it with a CTEC battery minder over three days, and hoped for the best. After the full charge light came on, I removed the battery minder. Three days later: battery dead again.

This time I hooked up a digital amperemeter between battery (-) and chassis ground. Comparing the excellent current consumption summary I read:

http://www.planet-9.com/cayman-boxst...en-parked.html

with my numbers, I noticed that my consumption constantly fluctuated between 4mA and 170mA. It never came to a rest, even after several hours when usually all systems in the car come to rest, except for small currents for background systems maintenance.

Even after the electric system had gone to sleep mode (ca. 2 hrs), when usually current drain goes down to ca. 2-4 mA, in my car the 170mA kept on draining the battery- whether the light switch was in 'off' or 'home' made no difference.

I undid the light switch mod, and the pulsing high current draw disappeared instantly and permanently, with my battery now holding full charge again. The car has now returned to the original 'sleeping' current draw of about 1-3mA.

Conclusion: despite having the same light-switch, wire colors, fog light and 'home' set-ups as a 997, at least on an '06 987 with PCM this mod does not work! If any of you with 997 or 987 have battery drain problems after installing the mod- now you know what causes it.

What could be the problem?
From what I read on various forums and heard from Porsche electric experts so far, these cars have quite a complex and intertwined electric system that will cause current drain through seemingly illogical means, and in the most unsuspecting areas: For example, removing the bulb from the front trunk, to save battery power during prolonged openings of the lid, will actually not stop current consumption (I measured ca. 50mA) it seems to trigger some type of warning current, though the whole electric system seems asleep.

The old concept of electricity only flowing when a user can be identified- light, radio, etc. - is dead. The only proof of current consumption being in order is to make an actual current consumption test at the battery and compare actual drain to the nominal drain for the vehicle in a given situation.

utkinpol

hi,

i heard some responses like this. other way to do similar mod if you want to sacrifice 'usual' way to turn on fogs - you can take apart connector itself, take out 'home' wire completely and insert 'front fog' pin into its place.
i posted same thing on 6speed and in responses i see that some people have this mod working fine and they leave cars with switch even in 'home' position and get no drain, others report that in 4-5 days it drain battery down. go figure.

other way is to put a diod between wires to prevent current drain from 'home' wire into 'fog' wire so it would only allow current to flow in one direction only when 'home' wire gets connected to a ground. it is a bit more difficult than a simple wire tap but not by much. i just did it this way on my car, with a diod. its legs insert fine right into wire pins (just get them out from a connector first, then push diod leg into it so you feel it`s secure) and then push pin back into connector. test if it works fine, then put tape over diod and put back on connector`s cover.
this way it should not be able to drain anything. diod`s cathode goes into 'home' wire pin A2 so current would flow from 'fog' wire A5 into 'home' only when 'home is connected to ground.

and like i said, folks - you cut and splice wires on a $100k car at your own risk.

Minok

This is a fact of life in electrical systems that have monitoring and fault detection systems as part of the overall electrical system. For every user on the electrical system there may be several monitoring circuits designed to signal if there is a problem or unusual behavior by the user. The Porsche system, with its complex and monitored addressable electrical consumers and ability to detect bulb failures, etc. would be a prime candidate for having new draws come on line when a typical user isn't functioning as designed. (unfortunately not always with an error indicator, if the way its misbehaving isn't a failure mode the designers built the system around)

utkinpol

i suspect there are diffs on how internal curcuitry was done in front ECUs on different MY in 997 cars. as different people seem to have different results. factory never guaranteed everything to stay the same.

so just do a diod way as i did show above. from what i think it should be safer than a wire tap.

ddd269

Great write up... I was looking for something like this.

One question. Did you have battery draining problems or noticed such before the diode install? In other words, have you left the car sitting for several days? Wondering if I need to do the diode at all. If you haven't had problems I'll just do the tapping.

I too have an 06... but a C2S. I don't think there would be a difference because mine is an S.

juniormarbles

The simplest test to check for unusual battery drain is to measure current drain before and after the mod/hack when the car's electronics have come to rest (ca. 2hrs) Then you will know 100% for sure.

It's as simple as lifting the ground wire that goes to the car's frame from the battery terminal and connecting the amp meter in series with it and the battery's ground terminal.

Any decent $10.- digital meter capable of measuring amperes will do. The range will be in the milli amps. (No user: around 2-4 mA, monitoring, door open, etc. <1000mA)

utkinpol

I had several different issues so I had battery drain but imho it was not related to hack but I never had a chance to fully investigate.
When I found out that there is voltage diff on A2 and A5 wires I already decided direct tap is not a good option as it will always have some current and I did not want any.
Put a diod instead of a tap, imho it is a safer way and works all the same.

ddd269

Thanks for the advise.


Will do about the diode. I was planning to change to one of those LED fog assemblies so this is a good fix either way. Thanks again.

Musclehedz101

Just re-did my mode for original suggestion and added Diode. I used heat shrink tubing around diode as insulator. It was a little snug getting connector cover back on but works great. Thanks for posting follow up.