Troublesome rear light (Spotback 2009- LED tail light) Bulb failure warning light

[c_w]

I keep getting bulb failure for my rear right outer lamp, it's the 2009-on "LED" type. On a hot day with the sun on it it works fine and the warning goes out, but 99% of the time it gives the error on start up and doesn't work. The wiring is fine upto the lamp I've checked that, but due to the design of the lamps it's not obvious where a bad connection may be or is there another thing to check?

Not even sure what kind of light the strip lights are? are they a true LED or a bulb that lights up a tube?

 

[210_MIH]

check out post - might help

http://www.audi-sport.net/vb/a3-s3-...2010-a3-sportback-rear-led-light-problem.html

 

[martinivw]

I keep getting bulb failure for my rear right outer lamp, it's the 2009-on "LED" type. On a hot day with the sun on it it works fine and the warning goes out, but 99% of the time it gives the error on start up and doesn't work. The wiring is fine upto the lamp I've checked that, but due to the design of the lamps it's not obvious where a bad connection may be or is there another thing to check?

Not even sure what kind of light the strip lights are? are they a true LED or a bulb that lights up a tube?

Its a LED that lights a tube, have you retro fitted the lights??? Do you have adapters??

 

[c_w]

Its a LED that lights a tube, have you retro fitted the lights??? Do you have adapters??

Yes they're retrofitted and came with adaptors, second set I've had and worked fine. To remove the possibility of the wiring harness being a problem I have rewired it to bypass the adaptor so I'm confident the wiring isn't the fault (at least up to the plug).

I did this partly becuase the wiring was going green due to water ingress but it didn't fix the fault (all pins were cleaned up). I might try swapping the lamps over left to right to ascertain if it's a lamp or wiring issue. I'm sure the factory harness is susceptible to water too, not a lot of resistance to water getting in!

 

[MrLapou]

If the wiring is green, it could be corrosion progressing inside the copper strands, which will go brittle and beak or lead to high resistance which simulates an open circuit.

 

[Ash187]

i was going to say sounds like you have got water in there... seen it happen before on someone elses car. make sure the wires are good and seal it up properly so no water gets in there