Rear speakers are not working... and missing fuses

[Bobby417919]

Well I noticed a week or so ago that the rear speakers in the doors were not working and every now and then the front right will stop working too. Seeing that I know NOTHING about car audio other then to turn it on, up and change CDs, I thought I would check the fuses. Non were blown to the radio or the rear door. So my question is, how would you go about trouble shotting this?

So when I checked the fuses I found the following missing.
8 - Telephone - Ok I dont have that np,
11 - Auto Transmission - I do have an Auto trnny but its tiptronic .. dont know if that makes a differences.
17 - Level, Tirepressure - Dont know if i do or dont have it.
19 - Fog lights, fog rear lights - The fogs work fine both front and rear..
20 - Dipper headlight Right - Them seem to work fine to me. I think they might be a little low. They also seem to auto adjust as well.
21 - Dipper headlight Left
27 - Towing Assemlby - Dont have a hitch

Should I put fuses in the missing spots?

Car info, 2002, Auto Trip, Bose Stereo,

Thanks for any help!

[diagnosticator]

You have OEM xenon headlights, and there are no fuses for the low (dipped) beams or high beams, or fogs in our A4s, either xenon or halogen headlights. Those fuses are only used in the lowline equipment setup, without a Central Electric Control Module, not available in NA market. Do not install fuses in the sockets marked for headlights or any equipment not present. You don't have tire pressure monitoring or auto leveling suspension.
Is your A4 a quattro or FWD? I will check the wiring diagrams for the existence of fuses for the transmission and Bose rear amp. However, the trans should have a fuse installed.

[Bobby417919]

I have a quattro. I'll look into getting a fuse for the trans tomorrow. Hopeful the speaker issue wont be that hard to fix. I like my tunes!

[diagnosticator]

I checked the wiring diagrams, and there is no fuse for the transmission. The Bose rear speakers are powered from R12 amp, and since only the rear door/s are not working, either the connection to those speakers or the speakers themselves are faulty.

For the intermittent front right door speaker, it's likely the wires to that speaker are broken at the rubber boot in the door jamb area. It's a bitch to check but unless you can find another problem, that needs to be examined.

[Bobby417919]

Ok so it seems the missing fuses are fine. Big thanks for the help!

Now the big one.. speakers... I guess the easy way is to get a speaker and swap them out. That begging said, can i take a front door speaker I know that works and try it on the back door? Of course if it works then I found the problem.. if it doesn't then its likely to be in the wires somewhere.. which im hoping its not.

[diagnosticator]

Sounds like a good plan to me.

[alpinestar180]

typically when a speaker doesnt work its not the speaker, its some interruption in the signal getting to it. you have to do something really crazy to actually fry a speaker with a stock hu and amp. try checking the wiring harness where it conects to the amp behind the carpeting on the passengers side in the trunk. there is a big harness there and if its loose that can account for the problem. also check the connections on the back of the head unit. If those seem ok, then its not all that uncommon for the stock bose amps to go bad every once in a while.