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Discussion Starter · #1 ·
Dear all,

I hope someone can help.

I recently changed the regular bulbs to LED H7 lights on my VW Jetta GLI Edition 30, 2014. After about 5 minutes of working, the left light went out, and does not work anymore, while the right one is still good. Checking the voltages on the terminals that connect the bulbs, I see 12 V on the working (right) one, but the left one only reads 0.5V.

I tried to identify which fuse controls these bulbs, but cannot find a matching fuse map anywhere online, none of them look like the one in my car. Checking the sticky on this forum, the mapping does not match with mine either.

As a next step, I unplugged one-by-one the fuses to see which one would turn off the right one. I failed to find the fuse that would turn off the right light, it keeps running. The only one that turned off a bunch of electronics, and the right light, was the one marked with 40 A on the attached image. I suspect this fuse controls a bunch of other electronics too.

Does anyone have a recommendation on how to debug and fix this? Is there some other way the supply may be cut to the front headlight?

Thank you,
Artur.
Electrical wiring Computer hardware Audio equipment Machine Gas
 

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Disclaimer, I dont own MK6 jetta nor I have debugged issues on one. But I have been VW for a while and here are my two cents.
Halogen headlights are usually not directly fused but are wired directly to the central electronics module which knows how to shut off circuits when it sees trouble. That is the reason you can't find any fuse. Here is my recommendation
Ideally you get a wiring diagram. (Its like $35 on vw erwin) to confirm what I told you. Or maybe you cant find it somewhere for free... I dont know.
Reinstall, original bulbs and try clearing module of any errors it has. You'll need VCDS or similar tool.
Its also, possible you "burned" the central electronics module but I would not go there until you confirm everything I said above.
 

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2013 vw mk6 jetta gli-Autobahn
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as already mentioned, it is definitely worth paying for a wiring diagram for your 2014. But, all other advice is where I'd start as well...especially checking for codes at the modules.

Also, have you checked the fuse box in the engine bay area, as well??
 

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Discussion Starter · #4 ·
Thank you both!

The car was originally not with Halogen headlights, just regular incandescent bulbs. Do they also have no fuses?

I also checked all the low fuses (<40 A) in the engine area, also no result.

I don't have a VCDS tool, is there any other way to solve it? Before I spend $35 on the wiring diagram, is there any other diagnostic I should do ? Since $35 is only for 1-day, I want to make sure I have all the needed tools before ordering.

Thank you
 

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2013 vw mk6 jetta gli-Autobahn
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basically, you need to trace the left wire backwards to find the fault, if it is only reading 0.5v. You might just have a blown relay. I suspect that a multimeter and wire diagram are your best tools at this time.

Some Autel scanners can provide detail module info too. Also, OBDEleven...


 

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I can't tell from your description, but did you verify that it was the bulb and not the wiring? Sometimes our cars don't like LEDs and depending where you got it from it could be forcing itself to turn off. I would plug the halogen bulb back in to see if it still works. If it does, I would say you have a faulty LED and pick one up from deAutoLED. Their stuff is great quality. If you did this already, I will go back to my hole.
 
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