A6 C7 Avant (Allroad) rear light errors / corroded connector

[mrming]

I have a 2013 C7 A6 Allroad, and recently had a dash warning for rear light / brake light.

Thinking the bulbs were gone I took the light cluster out of the tailgate to replace them.

It's a normal incandescent light cluster - not LED.

However when I removed the main cable for the light cluster I noticed a pin is very corroded (see pic).

I'm now thinking this might be the problem rather than the bulbs, as I replaced them anyway and the warning still pops up.

Has anyone else seen this? If I do need to replace a part, would it be the whole cluster, or are any parts available separately?

Any pointers greatly appreciated!

[Stevey Y]

1 hour ago, mrming said:

I have a 2013 C7 A6 Allroad, and recently had a dash warning for rear light / brake light.

Thinking the bulbs were gone I took the light cluster out of the tailgate to replace them.

It's a normal incandescent light cluster - not LED.

However when I removed the main cable for the light cluster I noticed a pin is very corroded (see pic).

I'm now thinking this might be the problem rather than the bulbs, as I replaced them anyway and the warning still pops up.

Has anyone else seen this? If I do need to replace a part, would it be the whole cluster, or are any parts available separately?

Any pointers greatly appreciated!

Hi thats an earth connection gone bad and heated up you wont get anywhere with that one I would also check the reciprocating terminal on the plug as it often burns that as well, only way round it if you don't want to buy a new unit and harness plug is if you can get into the back of the bit in the picture take the pin out replace the wire on that pin as far back as possible then either replace the pin or drill through the back of the grey  part just above the plug, run the new wire through that'd join it at the back of the plug wiring, correct cable for that terminal, if you put in a pull free connector on your new bit of wiring you can disconnect it any time you like.

Steve.

[mrming]

Hi Steve,

That's very helpful thanks! 

I may look at a new unit and harness plug as that seems like more my skill level and will still be cheaper than a garage.

Is there a possible reason deeper in the car do you think? Wouldn't want to fork out for it to happen again obvs.

Cheers,

Phil 🙂

[Stevey Y]

3 hours ago, mrming said:

Hi Steve,

That's very helpful thanks! 

I may look at a new unit and harness plug as that seems like more my skill level and will still be cheaper than a garage.

Is there a possible reason deeper in the car do you think? Wouldn't want to fork out for it to happen again obvs.

Cheers,

Phil 🙂

Hi Phil, no deeper reason I have seen a lot of this type of things mostly Ford headlights one of which took me two hours to cut and shut 30 wires and solder them, the earth wires on the plug side normally rot back under the plastic coating you can tell that because the wire underneath is brown and not bright copper, this is caused by moisture ingress and the only real way to stop it is put a hefty coat of silicone grease around the outside of the plug when refitting.

Steve.

[mrming]

Just to round this out, I managed to get a mobile auto electrician to visit and solder a new earth, so it's all working again now. Thanks for the help @Stevey Y! 🙂