Speaker buzzing - no output

[The911SC]

Hi All,
Just got back from the dealers. Car was in to rectify a buzzing speaker (rear right). The buzz is interference that changes with the engine and no audio output at all. The dealers ordered a new bose amp and speaker to be safe, fitted both but the buzz is still there.
I know its not the head unit since I have an rns-e which i retrofitted, and re fitting the concert 3 unit gives the same.

Any ideas?, the car is back in next week for them to take a closer look but I am stumped and wonder if I did anything in my retrofit?.

 

[AndyMac]

Has to be wiring if the amp & HU swap made no difference. That's all thats left.
My money would be on the rear right preout wiring between the HU and the amp. Probably the screen has come detached on the rear right signal, that would kill the audio and give you alernator whine. If it was anything else you wouldn't get anything from the rear right.

 

[The911SC]

Thanks Andy. Given its bose, is there a rear pre out feed to the amp?, and why would it just be one side?. Are the pre outs screened?, and if so, where are they earthed?. Given I have been proding around with the connector, I guess it could be this but not sure of the symptom. Is there an earth/screen pin to the HU in the green connector of the multi block?

 

[AndyMac]

Yes, yes & yes. Each channel is seperately screened and earthed at the HU and the amp.

 

[The911SC]

FIXED!. Thanks Andy (once again!) you were right.
I took the multi block apart and pulled out the green connector, releasing the black insert, I found the green wire was pushed right back. I couldnt re seat it and pulling it out (despite using a pin to press the tang down) resulted in it snapping. I pushed it out from the other side with a paper clip and extracted the broken plug.
I had some repair wires (the yellow ones with a clip at each end) so slotting a new one in, soldering it to the green and shrink wrapping it resulted in it all working..

It made sense really thinking about it but HUGE thanks, its now sorted and all back together with the rns installed.

Cheers Andy

Jon.

 

[AndyMac]

Nice one, how much of the car do you think Audi would have replaced before they solved the issue?