S3 - bose- Speaker buzz

[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?.

 

[Gti Jazz Blue]

Sounds like a cable problem then if they have replaced the amp and it happens on two different sources.

Was it OK before you retro-fitted the NAV ?

Paul

 

[The911SC]

yes, but it was also ok afterwards. I am trying to think back at when it could have gone and I guess it may have been a similar time to me adding the cd changer lead (which is not connected yet) but ready to be. (unless I broke a wire on the multi block?)

Its strange its just one speaker though if there is a cable fault?. Wouldnt it point to between amp and speaker?. Doesnt the bose work off a line in and as such would only have left or right out if there is a cable issue?
I am going to feel bad if the dealer finds something I screwed up somehow?.

 

[Gti Jazz Blue]

The Bose has a F/R fade function so I believe that there are four line outs and it could just be that you have damaged that one cable in the loom.

Paul

 

[The911SC]

Would that be from the Bose amp (which i havent touched) or the headunit?.
I thought the headunit just had a signal out?.

Thanks for your help !

 

[Gti Jazz Blue]

Head unit.

I will see if I can find the wiring diagrams from the Bose system over the weekend.

Regards,

Paul

 

[EAGLE79]

If it is still the same as older car stereos then a part has broken down and the name will come to me in a minute!

Basically it allows the enginereving to be transmitted throught he speakers. Heard and correctly fault found this a few times...

My brain has gone dead on the part name come boy

Give me time! LOL

 

[The911SC]

Basically it allows the enginereving to be transmitted throught he speakers.

 

[Gti Jazz Blue]

Right the wiring diagrams aren't very helpful in that they don't give the signals on the pin outs - however you may find that the sat nav will have the pin outs on a label on it. Certainly the Concert from my 2005 A3 does.

I doubt if it is the wiring between the amp and speaker as you wouldn't hear anything.

Sounds like either the output chanel on the source (NAV unit) has gone or the problem is on the line level connection between the NAV unit and Bose amp in the boot.

If you find that the nav unit doesn't have a diagram, I could send you a photo of the diagram from the top of my Concert as I suspect that they will be the same.

Paul

 

[The911SC]

thanks... Its strange though that I get the same result from both the nav unit and the original concert unit though which would indicate that the head unit is ok ( or both blown with the same issue?). Anyone know where the cable runs to the bose, or where the bose amp is?.
I have pin outs for the rns and concert as they are printed on the unit.

Cheers

 

[N8]

This happens in my 08 A3 with factory fitted nav...

 

[The911SC]

FIXED!. Thanks everyone who helped!.
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.

This forum is just great to talk things through!, it really helps..

 

[Gti Jazz Blue]

Great news - glad you fixed it OK.

Paul