So here's the deal:

I've never really used the CD changer in the glovebox, just tested it enough to notice that it seems to play CD:s, change tracks and so on but no sound can be heard. I thought it might be a defective changer. I recently ordered a Grom for it and plugged it in with the exact same results. It finds tracks (no track names/info though) and "plays" them but no sound comes out.

Radio, phone handsfree and other sources work normally.

I've thought about this for a while and the only thing I can think of is some kind of data communication issue. Be it in DA converter or wherever.

Has anyone encountered a problem like this and found a solution? It's slightly annoying as I can't listen to MY music instead of being limited to radio stations only.

Thanks.

 

How about BT from your phone for whatever playlist you like or with Spotify?

 

@hq_ ,
Can you post a picture of your infotainment head unit, is it original to the 2009 FS, or is it an aftermarket unit, have you looked for any other add ons that might have been installed prior to your ownership, unless you have owned since new.

Johnny

 

@BruceR : The system only has BT handsfree, not media capability, so unfortunately I can't try that. Adding BT audio was the main reason I chose to purchase Grom in the first place.

@Johnny Hotspur GT : It's a one-owner car I bought this fall, with a full authorized dealer service history and no modifications whatsoever. Bone stock OEM head unit with Naim. It also has the multi-pin connector for iPod/USB/etc. below the navigation DVD unit in the glovebox but no cables came with it so I haven't been able to try that yet. A USB interface cable is on its way from Scuderia Parts now.

The only possible anomaly I found were two wires, IIRC black and yellow, not attached to the CD changer multipin connector and taped off. I'll take pictures of these (as well as the HU if need be) when I go to garage later today.

All ideas are much appreciated. I already talked to a friend of mine, he's an RS-certified VAG mechanic running an independent shop and he couldn't tell off the bat what's going on. He's very used to repairing and solving problems instead of just swapping parts and he couldn't remember seeing a problem like this before.

 

@hq_ ,
Well yellow and black certainly sounds like someone cut the sound wires coming out of the CD changer to the Infotainment head unit, I will be back in a few, I will check the schematic and report back with a picture.

Johnny

 

@hq_ ,
So, as I thought, somebody cut the sound wires for some reason coming out of the CD changer, the yellow wire (pin 7) out of the CD changer is the LH audio, and the black (pin 9) is the audio ground, therefore, without the ground, the RH audio (green) wire (pin 10) is deemed non functional.
So pictures of the CD changer plug and these two wires would definitely help me to determine that they infact came from the changer, which at the moment looks to be 99% that they did.

Johnny

 

Thank you very much. This cleared things out quite a bit. So I dug into the glovebox as most wires were taped up and came across something interesting. An aftermarket BT receiver hardwired into CD audio wires. Ampire BTR100, stuffed tightly behind the changer.

Sorry about the large images but this makes the situation self-explanatory. No wonder CD changer and Grom were mute. This looks like a bit of a hack and the it's the very first non-OEM item I've found in the car. If this works, I wouldn't have needed the Grom in the first place.

Or alternatively, I'll fix this, use the Grom, rip out the Ampire and install it into my daughter's Volvo that has the integrated waterfall dash head unit with no BT. She's been yearning for that functionality for a while. And everyone's happy.

 

@hq_ ,
Interesting, you actually have 3 wires cut, the left, right, and ground, have you tried pairing your cellphone to the BTR100 ?

Johnny

 

I noticed the cut green wire too. The other ends of all three are connected to L+R RCA pigtail hooked to the BTR. I haven't tried pairing my phone with it yet, that's the next step now. As the HU doesn't seem to have other AUX input someone apparently figured out that by splicing into obsolete CD changer line they could feed the signal in from BTR when the HU is playing a CD.

Soldering them back together is easy but I'll test the BTR for laughs first. When I get the OEM USB adapter cable for memory stick this may be an acceptable BT audio solution as-is. In which case I have a spare NIB Grom. No problem, really, one of my business partners drives an early GTC and the Christmas is right around the corner...

EDIT: The BTR100 works, exactly as described above. Thank you one more time for the info & pointers, this might otherwise have taken a lot longer to figure out.

PS. As you seem to have lots of in-depth experience with these cars, do you have any idea where to tap into for constant, always on (not just acc) +12V near the glovebox? I'm planning to add a power socket to leave some 12V equipment charging in the glovebox when the car is parked and the diagrams that are commonly available are slightly inconclusive.