Bagwada

Hey all,
The headlights on my 2005 c230 keep going on and off all by themselves around every second or so. (See attachment)
Voltage is around 3v when off, 11v or so when on.
The wiring at the sockets is crap. The insulation is failing and someone has already put some electrical tape around some things. Does it make sense that this would cause the lights to go on, then off, then on, then off? What else can I look at to try to diagnose this problem?
Thanks
Ben

C230 Sport Coup

If the vehicle senses a short, or open circuit, yes, it will turn off the circuit.
Any bit of excess resistance counts as open. Do you have Halogen or Bix?

Bagwada

Do LEDs count as Halogen? Definitely not Bix.I have LED H7s Brand new.

KevinH2000

C230 Sport Coupe pointed you in the right direction.

If you have installed LED bulbs, I expect that they draw less current than the OEM halogens. This causes the control module to interpret the lower current draw as a defective bulb and it cuts power to the circuit.

Here's an earlier thread that discusses the subject.

You may be able to "trick" the system by adding a resistor to the circuit to increase the current used by the LED, but I think it would be better to have someone recode the control module to show that the car has Bi Xenon headlights. This video shows the process for using the Star system to code for "Xenon Present."

C230 Sport Coup

I believe I've seen cables that fix this problem, use a capacitor or something to fix the problem.
Putting a resistor on the headlights to add 20 watts of resistance would be some healthy resistors
and would get very hot. Back in the day I had resistors on my parking lights to use LED's.
They got prettty hot and had to be mounted outside the light housing.
And that was to only shed 2 watt of power!
Now you can get LED's that are Canbus ready.
Do they sell headlight LED bulbs that are Canbus ready?
I don't know I went to Bix 15+ years ago.
EDIT: Quick search shows a multitude of CANBUS ready LED headlight bulbs
mostly off brands. Go with Philips if you can find them. They last FOREVER!!!
No joke!

C230 Sport Coup

Bagwada

I replaced the crappy wiring harnesses on both lights. The passenger side low beam, blinker and parking lights are good now. The high flashes on and off. The driver side has no lights at all. It is drawing about 4 amps.

Do I need to reset the SAM or something?
other suggestions?

Petethepug

I’m not a fan of the individuals who run led retrofit lamps in housings designed for incandescent bulbs. Thank you for letting us know up front they’re LED.

That being said, the projector beam headlamps do a hell of a job putting the light down in the proper manner. LED and vehicles with ECU don’t mix until …..

This company, who integrated a fan into the lamp. It draws enough load to allow the system to believe there’s an incandescent bulb in there.

Installing those in the high beams will get me ranting.

Ursprung 2024 Upgraded H7 LED...

C230 Sport Coup

Sorry, whats the issue that's got you grousing? Those lamps you mentioned, 30,000 Lumens?
Seriously? Talk about overkill. Standard 55w legal bulbs have ~1500.
The only place I'd even consider something like that would be the brights. And that would upset you....how?

Since you're the one that posted these, why would you not want to use them for brights?
Use them as your full time normal beams will likely cause accidents by drivers who have been
completely blinded, and if installed as hi beam, better be quick on brights switch off.
And how long before the sheety fan gives out and melts the wiring, and probably the whole light assemby?
I would not recommend those. Not now, not never. (As the lizard says)

Bagwada

I think it’s hard to blame the bulbs in this case since one side is working and the other not even if I switch bulbs. The blinker and the parking light aren’t working either.

Petethepug

I gotcha, both of us rant (grouse) about LED when used in high beam reflectors made for incandescent bulbs. They bleed light into oncoming traffic blinding them.

Hella, Morimoto and other similar Projector assemblies running DS1, DS2 (HID) or LED have a razor sharp cut off to safely direct the light. In EU standards the xenon/BIX or LED usually require manual or auto leveling technology.

Re: A burnt harness… LED in general uses approx 90% less energy. If that micro fan went out, the LED board would go out because it doesn’t have the heat sink that LED normally come equipped with. The remaining 3-4v draw the LED would be consuming would not fry a harness, but …

Flashing… Low current draw will freak out the SAM. It would make LED headlamp flash on & off as pictured or not work at all. The SAM for the left headlamp is flashing, the right SAM is keeping the circuit off. Both SAM are freaking out. Hopefully replacing the OEM bulbs will get things back to norm.

Sounds like the the 30,000 LM being referred to isn’t specifying that it’s for both bulbs. Civilian LED technology does currently top out about 15k LM per bulb due to bulb, chip size & thermal capacity.

112233

Sylvania/Osram sells approved LED bulbs for Europe now, they draw 20W and have 5 times lifetime of a halogen but not cheap. And funny, they have 1500lm, because more is not allowed (without automatic leveling) When I remember correctly the normal H7 has 1100-1200lm