another taillight failiure, audi b7 2007 avant quattro

[xxxvrsix]

hi all, already read several threads about this problem. but mine is specific.

so here it is.

1. brake light faliure light up on the dash board

2. i change the lightbulb, nothing happens

3. i then proced to disasemble the wire harness

4. the brown wire on connector was a bit burn and plastic melted around.

5. cut the brown wire from conector, soldered new ground wire to metal rail inside the lights holder, soldered the new wire to brown wire from connector.

6. still nothing hapens.

i have tried to measure without bulb i get 10v of voltage, with bulb nothing.
everything other works fine.

this one light bulb is for taillight and brake, on the other side works fine, taillight is dimmed, whan press brake full power.

the bulbs are p21w...

any suggestion as what i can check more???

thank you

[ChanceA4Parks]

Have you tried swapping the bulbs with a known good one from the other side?

[texadelphia]

I had a similar issue and one of the contacts inside the plug was brown and discolored while the other contacts were bright silver. It looked like the one contact had corroded. So I wrapped a very thin strip of emery cloth around the end of a flat micro screwdriver and pushed it in and out of the contacts a few times to remove some of the discoloration. Reconnected it with some plug grease and haven't had any problems since.

[SlvrArrw]

I just had a taillight issue on b7 sedan.
Went the bulb route, also had melted ground terminal in plug.
So far, my latest solution: Bypass the brown ground wire. I ran a ground from the body in through the taillight breather( rubber cover) and soldered ground wire directly to tailight grounding metal. Light is brighter, no dash errors.
May need to do the other side now.
As these cars age, grounding becomes an issue. I know I had a short somewhere, however, the bypass is working.
Goood Luck.

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[Charles.waite]

That short is sadly common. Somehow that connector isn't sealed well enough and it arcs until is melts.

OP that ground needs continuity to the main ground that wiring goes to. You can't just ground it wherever or else you get bulb outs still I believe.

[Jay-Bee]

Had it happen to my Avant as well, cleaned the corrosion off the terminal blades with a small file and packed the connector with dielectric grease. Was going to perform this fix but it's been good now for over a year.

https://www.audizine.com/forum/showt...aillight-Issue

[Charles.waite]

I’d be really careful with dielectric grease on these. I absolutely flooded both sides of the connectors and every couple weeks the dielectric would screw up the ground and trigger the bulb out. I’d have to remove the light and reconnect 2-3 times and it would be fine for a couple more weeks. I finally got fed up and blasted out as much of the dielectric as I could with compressed air and it’s gone away I believe.

But learn from me and don’t just slather that stuff on...

[Snert]

I had to deal with pretty much replacing both the wiring clips for both taillights and using a wire repair kit to do so. Apparently this is a notorious issue for these. Find the connecting clips, snip the wires, use a wire repair kit and you should be golden.

[xxxvrsix]

I have replaced lights, from the other working side, same thing.

i was hoping this problem would go away with ground bypass, but nothing....

[xxxvrsix]

as soon i turn the ignition key i get left brake light yellow error.....

[EvolutionArmory]

If the ground wire in the harness was burnt, would it be safe to assume that the pin in the bulb tray is burnt too? Maybe you need a new bulb tray. I see you said you swapped from the other side so maybe not. Also, if the ground wire was burnt at the socket connector, I wonder how far back you cut that wire out? It might be burnt further back where you can’t see it.

I would get a hold of the wiring diagram for the tail light and see where the ground for them is. Maybe check the condition of that ground. You could also trace the harness wires to whichever module runs the tail lights. I forget which it is but will be written on the wiring diagram. It could be central electrics or comfort control. Who knows, you might need to run an overlay ground wire from the control module to the tail light. It’s possible that your extra ground didn’t cure it because these are Can Bus cars and it’s still seeing a break in communication.

You can download wiring diagrams from ELSA online. You’ll have to register and pay a small fee for 1 day usage. While you are registered, download as many useful things as you can think of 😀

Erwin.audi.com

[Charles.waite]

When mine failed, the pin on the bulb holder was melted down to a nub and I had to replace the taillight housing. I forgot to mention that. Just cleaning the contacts wasn’t sufficient.

[SlvrArrw]

Just a note here. My ground bypass is working for me as I stated before, no CEL or other bulb errors. However, I recall that I upgraded my engine compartment grounds . Since we know grounding is an issue with age, that is one thing that may helps us.

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[xxxvrsix]

thanks all wiling to help, went to the mechanic, first thing he was saying is the bypass ground, seeing that i have done that, he changed light bulbs, and quickly turn of and on the ignition key without starting, stating that it restarts the lights control module....

the bulb was new and working on other lights, but not in the light/brake hole.... i have no idea why....

well it worked, and it is working fine now...

[EvolutionArmory]

Fucking can bus....🤣🤣🤣

[SlvrArrw]

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[Supersquid]

I experienced this and feel fortunate. Bukdb


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[Supersquid]

I experienced this and feel fortunate. Bukdb


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I experienced this and feel fortunate. Bulb started working again once I touched it to remove. That was a few weeks ago and things are good so far. FWIW, the taillight housing isn’t sealed very well. That may be added to the list of “spring items.”

I was also experiencing the brake lights coming on. Figured it was a faulty brake switch (which it may have been) because the brake lights were on all the time.

I replaced the brake switch with a NAPA part. Don’t do that. Get the Audi one. Ask me how I know. Installed the correct AUDI/VW one last week and still had the problem for a couple days. Everything’s been good this week.

Who’dathunk taillights could be SO troublesome?!



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