Mikael Lindskoug

weaker light in forward


Full function when turning
I had an inspection of my Porsche Cayenne turbo from 2005 with Xenon lights and it is equipped with cornering lights.
I have the light switch on and on auto.
They work fine - when turning to the left the left cornering light is fully on and when turning right the right light is turned fully on.
BUT the lights are always on, even when I'm not steering to the right or left.
The lights are on but with a weak light and when turning they are fully turned on in the correct direction.
Is this normal or do I have an issue (like grounding) ?
(The side lights are also always on, one is broken).

Anyway - I failed at the inspection because they are not fully switched off when going forward.

deilenberger

That's not right. I'd be looking at the wiring between the main harness and the headlight connector behind the headlights, and I'd look at the wiring within the headlights. Both are known to shed their insulation - and a short between bare wires could account for these being on. A bit odd that it happened on both sides.. but it does happen. You'll have to remove the headlights to inspect this - there are instructions on doing that in your owners manual. The other option if no bare wires are found - to pass inspection - while the headlight is out, just unplug the bulb for the cornering lights. I'm sure there is no requirement that they have to turn on or work.

Mikael Lindskoug

Thanks, then I know what is correct. I'll check the wiring. I have removed the headlights so many times so I'm a specialist at it now.
On the left side I have probably broken a wire when replacing the side light bulb, on the right side I dont know.

I think the manuals are lousy about when replacing the side light bulb ( T10 ). You have to twist the holder about 90 degrees and nothing is mentioned about it in the manual.
I dont know if the lights are original - they are from VALEO. Maybe thats the reason.

Kimple

I have 2004 CTT and it works the same way. I always thought it was normal.

Petza914

I think my low mileage 957 is the same. I think k the lights are, always on and what happens when you turn is that the shield in front of them is moved out of the way to illuminate that corner toward which you're turning, then when you straighten out, the shield moves back into place.

Yes, the side lights are also on with the parking lights or headlights. I think you can code these with Durametric to work as direction indicators instead of just running lights, at least you can in the 997s.

Mikael Lindskoug

It's confusing. I asked a friend of mine to check it. He has a Cayenne Turbo from 2008 and his cornering lights are totally switched off when not turning.

deilenberger

Have you checked the wiring yet? It's not a difficult job..

Mikael Lindskoug

How do i check the wiring?

I have printed out the wiring diagram, but how do I check the wiring (which of course has colour markings so it is easy to identify the cable) when I have the headlight unit on the table/bench?
Normally when checking things I switch on everything and I measure if it is 12 V or grounded, 0V.
But when the unit is installed I can not check it and reach with a pen.
On the bench I could could check the restistance from the contact (broken circuit)?

On the other side - I have a Duremtric log that does the job for me (probably) and it clearly says that the left side is broken (broken circuits).

Next week I will replace the the unit since side light holder also is broken.

deilenberger

Remove the headlight. LOOK at the wiring going to the plug on the body. Is all the insulation there? if so - it's OK - if not you need a new section (fairly cheap and plugs in)
Open the back of the headlight. LOOK at all the wiring inside the headlight, is all the insulation there? If so - it's OK - if not - dunno that they make a replacement harness for inside the headlight. You may need someone with electronic skills, or it may be time to consider new headlights.

Easy. 5 minutes per side. If one side is toasted - you can assume the other side is too.

Kimple

I still think it is normal. Look at the pictures in this thread: https://rennlist.com/forums/porsche-...955-ttc-5.html
As you can see, the cornering lights are lit but dimmed when not turning.
If there are wiring problems you would see flickering, random dimming, etc.

Hal 2000

This has been the same for me, with the dim cornering lights when not turning. It has passed every NYS Inspection since I bought my 06S in 2009. I think it is normal. Cornering lights work fine otherwise.

Mikael Lindskoug

Kimple: Thanks for the photos - Obviously they are on. (I have no flickering problems.)

Deilenberger: I have now verified "wiring going to the plug on the body". They look healthy on both sides
**
I have now replaced the left headlight unit (< 400$ !) and all the errors in the Durametric log vanished and it is clean. There were som false alarms that also disappeared.
There were som broken wires on my left unit; probably broken when I tried to replace the parking bulb.
But still cornering lights on. Probably it is normal on my car.

To summarize: How do you test and verify when having electrical problems? Buy and use Durametric software (about 200$) and it is easier than using a voltmeter.
It helps you in two ways:
1. The work log indicates which wires that are broken. Compare with my log that is attached and when having broken left headlight unit.
2. You can cycle through and test component for component using the software and by pushing a software button. Left dipped beam, left parking light, right.., horns, washing pump and so on. Very easy.
( I discovered that the right wheel arc indicator bulb (W5W ?) was broken.)

tjrob2000

I'm certain they are always on as mine are as well on my '06 CSTi. If they are unplugged you get a cornering light error on startup. Petza's description makes more sense than having the bulbs turn on/off.

Mikael Lindskoug

Some final words:
The headlights are OK and they should work like my initial descriptions. It was wrong of OPUS (who was doing the inspection) to reject my car.
I went to the Porsche Center in Stockholm, Smista and the mechanich said that the headligts/cornering lights should work like this.
Even the authorities (Transportstyrelsen) said this rejection was strange. Now I don't want to waste more time on this and hopefulley someone else can hase som use of this info.
.

Dilberto

This is normal, OP. The cornering lamps stay on, in a low power state until the steering wheel clockspring trips a turn being initiated. It then goes full bright, until the wheel straightens-out again.
Bonus FYI - when in Reverse, the cornering lamp shines in the OPPOSITE direction of the steering wheel being turned... which I find somewhat useless, as you are traveling in Reverse and not looking forward anymore. Teutonic logic, for you right there!