Xenon troubleshooting

[Inex]

Hi all. Never had a xenon failure before so I'm not quite sure what I'm doing with this so here goes:

 

Bought the car with a super small crack in the headlamp on the bottom part that's paralel with the pavement but still outside. It was all misted up. Finally a few days of sun have arrived and I had it sit in the sun and it almost entirely dried up.

 

Overnight it all came back so a few days after I go on a 1k+ trip only to arrive and notice the xenon bulb was flickering on off in an irregular pattern. (No errors in the dash yet)

 

Left it overnight, the next day that right xenon bulb does not even turn on so I was content it probably died.

 

Meanwhile, I had the chance to leave the car in the sun with an open Bonet and an open headlight assembly so it vents out properly. Misting never came back (even after several rains and 3 weeks since) but my xenon bulb is still dead.

 

Went to a store, bought the cheapest D3S and temporarily connected the plug to the bulb and left it hanging behind the headlight (didn't want to bother removing the old one yet). Turn the car on try both high and low beams and nothing... So I return the new bulb...

 

A little upset at this point as I feel like it may be a more expensive fix...  I get home, remove the faulty bulb and notice the ball inside is orange and yellowish. Probably burnt but I go ahead and connect it to the other hedlight the same way by leaving it hanging behind the assembly. Obviously it does not work.

 

So if my old bulb is burnt, doesn't work and a new one doesn't work either, what could be the cause? (I don't have access to my vcds at the moment) Trying to anticipate a few things before I get my hands in it again.

 

Just to be 100% sure, the bulb in the picture is dead, right? I also uploaded a picture of the inside, in case you can see anything wrong or out of the ordinary. 🤷‍♂️

[numskull]

I don’t know if that’s normal or not, but it doesn’t look like that’d be normal. I hope water hasn’t entered the headlamp itself and caused damage and thereby the issue, primarily because I understand the replacement cost of the headlamp unit is absolutely horrific. 

[Inex]

Yeah.... I plan to try to swap the ballasts around over the weekend to see if that indicates anything... Crossing my fingers it can be done without removing the headlight.

[Danoid]

I suppose you’ve already checked the obvious being a fuse?

[JR RS]

3 hours ago, Inex said:

Yeah.... I plan to try to swap the ballasts around over the weekend to see if that indicates anything... Crossing my fingers it can be done without removing the headlight.

 

In addition to the ballasts, also swap the control modules - there r 2x per headlight, underneath.

 

Ballast u can swap without removing the headlight.

 

Unfortunately with control modules, u'll need to get access under the headlights.  Easiest way is front wheels off, wheel arch liner off - u will the have access to the back and underneath the headlight.

Alternatively, try removing the engine under tray, u might b able to reach the modules, with long skinny hands.

 

Sometimes these modules can get affected by too much moisture build up inside the headlight and subsequently fail.

 

If swapping the 2x modules and ballast make no difference - then u'll likely need to replace the whole unit.

 

.... assuming ur fuse is fine.

Edited 16 April by JR RS

[Gabrielem]

Take advantage and install LEDs. Many best.

[Danoid]

3 hours ago, Gabrielem said:

Take advantage and install LEDs. Many best.

Not legal here in UK

 

Edit, fit Osram NBL LED if it’s legal in your country!

Edited 17 April by Danoid

[Inex]

On 16/04/2024 at 23:43, JR RS said:

 

In addition to the ballasts, also swap the control modules - there r 2x per headlight, underneath.

 

Ballast u can swap without removing the headlight.

 

Unfortunately with control modules, u'll need to get access under the headlights.  Easiest way is front wheels off, wheel arch liner off - u will the have access to the back and underneath the headlight.

Alternatively, try removing the engine under tray, u might b able to reach the modules, with long skinny hands.

 

Sometimes these modules can get affected by too much moisture build up inside the headlight and subsequently fail.

 

If swapping the 2x modules and ballast make no difference - then u'll likely need to replace the whole unit.

 

.... assuming ur fuse is fine.

Thanks buddy. Good to know small details like that before jumping on it. Plan to take it all one at a time over the coming days when I have the chance. 

 

For the modules part it clearly requires a longer time before all that comes off and I manage to orient myself around them.

 

Any idea if a bad ballast has the potential to burn a bulb? It would be ideal not to burn the second bulb when doing the swap around 😅

[Inex]

Okay, after putting some 2 hours into this:

 

- checked the fuses (11 and 24) both are fine. It seems there are 3 variants of the fusebox for this vehicle...

- removed the right side ballast and put it on the left with the good bulb > didn't work (need to detach the oil filter and move it out of the way to reach the screws) 

- removed the left side ballast, tried it on the right with the bad bulb first > didn't work (need to detach the ECU wiring harness from the frame to reach the screws)

- tried the good bulb on the right with the good ballast > it worked! So I can rule out the headlight unit and its modules

 

I've done done all this by disconnecting the battery every time I had to touch the ballasts.

 

VCDS is on its way to me but I guess this calls for one new ballast and one bulb.

 

Question is: will the new ballast and bulb combo on the right be brighter than the left? Will it trigger my OCD? 🤣 

[JR RS]

Nice work in diagnosing the issue.

 

With regards to ur OCD, yeah, in theory the new bulb will shine brighter, especially if ur other one is a couple of years old.

The ballast won't affect the brightness if it's the same power/specs.

[Inex]

22 minutes ago, JR RS said:

Nice work in diagnosing the issue.

 

With regards to ur OCD, yeah, in theory the new bulb will shine brighter, especially if ur other one is a couple of years old.

The ballast won't affect the brightness if it's the same power/specs.

Perfect then. I ordered a new set of nightbreakers and an identical ballast 💪 

[Danoid]

Have you resolved the issue with the crack? 
 

It might be small but could just be enough to have caused the issue, clear epoxy might do the job but only guessing

[Inex]

4 minutes ago, Danoid said:

Have you resolved the issue with the crack? 
 

It might be small but could just be enough to have caused the issue, clear epoxy might do the job but only guessing

Not yet... The headlight assembly seems totdry up quite easily be removing the rear caps and I have not had 1-2 continuous dry days yet. I plan to seal it before refitting the new parts.

[Danoid]

19 hours ago, Inex said:

Not yet... The headlight assembly seems totdry up quite easily be removing the rear caps and I have not had 1-2 continuous dry days yet. I plan to seal it before refitting the new parts.

Ah remember that when you use your headlights you’ll see condensation by the DRL’s which is perfectly “normal”, but I guess the crack let in rain water which then trickled down to parts it shouldn’t and caused the issues

[Inex]

So, new ballast and a brand new pair of nightbreakers came in and had them fitted over the weekend 👌 The car was equipped with standard Osrams before. I installed one bulb at a time so I would have the opportunity to drive in the night once with two different bulbs and tell the difference. The nightbreaker bulb is indeed brighter and from a distance it has a purple ish tint.

 

As for the install, I spent 30 mins on the right side ballast by easily moving the fuel filter canister out of the way and an outrageous 1.5 hours on the right side bulb and almost 3 hours on the left side bulb...

 

The right side bulb I managed to fit the metal clips back together via the tight gap behind the headlight. For the left side bulb I gave up after 2 hours of breaking my hand inside through the gap behind the headlight and decided to turn the wheel max left and remove the Inner Wheel arch plastic just enough to fit my hand through there only to realise it took 1 min to fit the bulb this way... I suppose you would remove the wheel normally but I do not have a jack stand or anything to lift the car so I gave this a try with success. There are in total about 16 torx screws you need to remove for this and this is for only half of the wheel arch. Nevertheless, it is possible and that's what I will be doing next time if need be.

[Danoid]

The correct way to change them is wheel off and then remove wheel arch liner.

 

I not long changed my xenon’s and even with the wheel archer liner off I really struggled clipping them back in with the non SLA version, where there is two metal prongs you move.

 

It’s such a simple locking but because of the tightness I could only use my right hand and I’m left handed, so I put it down to my brain not working properly 😩

 

SLA version is turn bulb anti clockwise to unlock then pull out and clockwise to lock it, much easier I imagine

 

Glad it’s all sorted, guess next up for you is to get a decent trolley jack and axle stands and do other bits yourself now