Need Help with Bose Audio Issue [Archive] - Audi Forums

: Need Help with Bose Audio Issue

12-27-2011, 01:00 PM
I am having a problem with my sound system in my 2002 Audi A4 with the Bose Symphony system.

Radio On (on any source) but no sound. This is intermittent and has gotten progressively worse, now to the point where it rarely gives me any sound at all, and then only for a few seconds at a time. Radio displays that it is working properly but no sound.

I have looked into many possible solutions and have narrowed it down to either the Amp or a short in some wire somewhere. I need help figuring out which.

I know it's not the radio because I have the same issue with my brand new Sony head unit. I'm sure I have the aftermarket head unit installed correctly because I hooked up the audio outputs (which would normally be outputting into the stock harness via an adapter) to a portable sound system and I got working sound.

The problem is either happening on the way to the amp, in the amp, or some sort of issue with wires going out of the amp to the speakers which is causing the amp to stop sending sound to all speakers.

I'm aware that there are a few common places where there could be a short (like between the door jams) and I've looked there. I did actually find some frayed wires in the driver side door jam and I taped it up. Is it possible that taping the frayed wire isn't enough?

I checked power going to the amp and it appears to be working. The switched power to the amp is also sending power correctly and I can audibly hear the amp turning on correctly. I checked for DC voltage going out to the speakers from the amp and I did not see fluctuation as if audio was being transmitted, but I'm not sure if you can see that on a meter.

I opened up the Bose Amp and it looks as clean as can be. Everything still has a nice gleam on it and each and every solder joint looks pristine. I was hoping to be able to see some sort of visual sign of the amp going bad but I was disappointed.

How can I verify the amp is or isn't working?

How can I use a volt meter to help find a short with out taring apart my car? The clips on the door lining are so fragile I don't want to go breaking a ton of them checking each speaker. How can I test each speaker independently?

Can someone please point me in a direction or tell me what to check to help narrow down my issue?

Thank you for taking the time to read this whole post,


01-02-2012, 06:30 PM
My solution was to replace the amp in the trunk.

I found an amp at a semi-local salvage yard (100 miles or so) that shipped it to me for $150. Bit more than I wanted to spend but I was desperate and the shipping only took about 48 hours. The new amp works perfectly and my stock Bose system is fully functional again. I'm still waiting for one last part before I complete the swap over to my new aftermarket head unit (steering wheel controls adapter) but everything seems to be working flawlessly after 2 days of testing.

For people in a similar issue I would do the following:
1) look for a short in the wires in the door jamms by unclipping the weather strip from the car (not the door) and checking as best you can for frayed wires. There are 4 clips holding it against the car, undoing the 2 outside ones will allow you to wiggle the clip with your hands to get it completely lose. You should replace the wiring harness if you find broken wires but you can be cheap like me and just tape it up to prevent a short.
2) Check to hear if you can audible hear the amp click on and off when you turn your radio on and off.
And if your really feeling in a testing mood:
3) Unclip the amp wiring harness and use speaker wire from a portable (or in my case, not so portable) stereo to the correct pins in the wiring harness to test that the speakers are working. You can find a wiring diagram for the wiring harness online.

I don't think it's a good idea to just replace the amp without making at least some effort to look for a short because it may (or may not) be possible to break a second amp if you don't fix the short. I could be wrong here but I'd say it's worth the effort.

Good luck,