led rear lights

[oldgrowler]

Hi everyone, I have a few led bulbs out in the rear lights on my 2005 a8 and wondered if anyone has managed to replace just bulbs in circuit board and if so what spec led bulbs I need to buy? Apparently its quite simple to remove light unit and I have a mate who is pretty handy with electronics so has anyone got experience with light unit removal / parting and re- sealing? Any tips would be grateful and bulb type would be perfect.

[meffe]

Hi mate, I had the same problem. Just remove the circuit and solider on a new set of led's - u can get them from eBay, but you might have to try a few as the colours may vary. Get the highest mpcd rating bulb as the originals are bright. It's an easy fix and not difficult. Changing the unit would cost a few quid so you'll save some dosh!

[oldgrowler]

thanks for reply, i was hoping someone on here had already attempted this and now i know its possible which is great. did u have to part light unit? if so can u give any tips?

[meffe]

thanks for reply, i was hoping someone on here had already attempted this and now i know its possible which is great. did u have to part light unit? if so can u give any tips?

Removing the light unit is quite easy, the cirucuit board is connected by clips to the lens cover, which can be pulled out. Once you access that, you will see the bulbs and circuits. Before removing the cable power connection - note which bulbs need replacing, then buy the appropriate bulbs - 2-pin LED. Mine were clear with bright red light (13000-16000mcd). Check these first on ebay. Once you have a few samples, you can check which is suitable to match the others. You can also try local Maplins store - i did this, and just bought a few of each, but they didnt have the bright light as the unit originally has.

[Micha_elD]

You might find the LEDs are fine, but some damp has got in there and corroded the connection. I managed to open mine up, but I'm so lousy at soldering that I repaired 5 and broke 8 others, so it all just got worse until I bought a new light and promised never to open it up!

But if you've got a mate that can solder, ask him to just go over the existing LEDs first and see if that makes it good enough

[oldgrowler]

thanks for advice, glad you mentioned about noting which led's were out before removing light as thats the sort of thing i might forget when i get carried away dismantling. just need a sunny dry day now to get on with the job

[oldgrowler]

update, we have taken the rear o/s outer light apart and have found out the indicators not working are due to a circuit board and im wondering if anyone knows where i might get a replacement board?

[meffe]

update, we have taken the rear o/s outer light apart and have found out the indicators not working are due to a circuit board and im wondering if anyone knows where i might get a replacement board?

What exactly is the problem with the circuit board? Is there moisture/water damage?
Audi will not sell as a single circuit board, they will sell this complete, which is expensive - that's why i repaired mine.

If you can explain to me the issue, i have an electrical whizz kid at work, that could find a solution.

[Micha_elD]

Your best bet is to look for a secondhand replacement. Put the part number into eBay, set the search to look across the whole european union, and you'll find a few at German breakers.

To get you started, look for A8 Rückleuchte and you'll find a few, about £100 inc. postage, but part number will likely find you more options. Yours is an A8 4E. Surprisingly, lights for the newer A8 (the 4H) are cheaper. Suppose thats because they haven't started failing yet so there's no market for them.

[oldgrowler]

@meffe we believe its the main circuit board not the led circuit board as we have power coming to the black plug that supplies the led boards only showing for rear lights and brake lights, indicator supply is odd because immediately after switching indicator or hazards on the led's very faintly glow then disappear and pulsating power to black plug is none existant and this will happen everytime, my mate believes its a capacitor failed but due to the board being a complex dual layer we cant test the circuitry with out a circuit diagram as we wont know how the board is set to work with plenty of relays,capacitors,fuses etc. would love to find a circuit diagram to at least give us a chance. thanks for reply and if your mate has any ideas please pass them on.

@micha_eld thanks for reply ive already started searching for lights but not sure a second hand led unit would be a wise buy when i can get a new unit from audi for £200 although thats still a crazy price, i am toying with the idea of upgrading the entire 4 rear lights to the latest facelift ones as ive been told they are sealed units on the outers and im wondering if they are a better option as they shouldnt suffer from the condensation the same way these ones do.