I have a 2005 S4 (same dash as any B6 A4 or S4) with the Bose package. I've done a number of head unit installations in the past, but I think I'm in a bit over my head with this one.

Here are the issues/questions I have:

1. What's the best way to get switched power to the unit? I'm using a wire tapped into the fuse box for the windshield wipers, which works, but I'm wondering if there's a Can-bus adapter somewhere that would be better?

2. How can I get the illumination functionality to work? My understanding is that this is also tied to can-bus with the factory stereo, but I have no idea what to try to tap into to get this working.

3. What do I do to get the radio antenna to work? I've got an adapter which fits, but I barely get any radio reception. I've heard that these cars use some sort of powered antenna, but I have no idea where to even start with this.

4. Where do I route the GPS antenna? I'd love to either tie into the sharkfin in the roof or replace the factory GPS that's in the sharkfin. Tying into the sharkfin seems difficult because I'd need an adapter to plug into the back of the avic (proprietary Pioneer adapter) as well as an adapter to plug into the factory GPS harness, which is some sort of odd adapter as well (fakra?). Suggestions?

Once I've finished the install I'll try to write up a guide as there isn't a ton of detailed information out there all in one place.

Thanks in advance.

I have an '02 A6, but the setup is almost the same...

1. What's the best way to get switched power to the unit? I'm using a wire tapped into the fuse box for the windshield wipers, which works, but I'm wondering if there's a Can-bus adapter somewhere that would be better?

 

2. How can I get the illumination functionality to work? My understanding is that this is also tied to can-bus with the factory stereo, but I have no idea what to try to tap into to get this working.

Get the CAN Multi from soundgate http://www.soundgate.com/index.php?request=product.details&categoryid=262&productid=590&usereferrer=1&, that way you get illumination, switched power, and VSS.

 

3. What do I do to get the radio antenna to work? I've got an adapter which fits, but I barely get any radio reception. I've heard that these cars use some sort of powered antenna, but I have no idea where to even start with this.

You have to get an amplified HF adapter ... you connect the blue power lead to the blue antenna power from the head unit. This powers the antenna booster in your back window. Without this, you get no powered antenna, and thus static. This adapter is hard to find at local stereo shops, I typically have to find it online: http://www.crutchfield.com/S-w5TYHmhWsiV/App/Product/Item/Main.aspx?i=12040VW54

4. Where do I route the GPS antenna? I'd love to either tie into the sharkfin in the roof or replace the factory GPS that's in the sharkfin. Tying into the sharkfin seems difficult because I'd need an adapter to plug into the back of the avic (proprietary Pioneer adapter) as well as an adapter to plug into the factory GPS harness, which is some sort of odd adapter as well (fakra?). Suggestions?

There's no tying to the existing gps antenna. You've got to install the one that comes with your head unit. So an easy/effective way that I've done this is use the metal plate that comes with it and stick that to the rear deck, behind the child LATCH point. You can snake the cable up through the child latch point hole, so that you don't have to drill a hole in your rear deck. Just put that magnetic plate as far back in the window as possible, then drop the gps antenna on top of it, the magnet inside will hole it right there. Additionally, there's plenty of room on this metal plate for the sirius antenna as well, if you go that route. [/url]

You sir, are awesome. Thank you.

My problem is that I didn't figure all of this out until I spent two weeks screwing around with my car and spending money on adapters that didn't do the job.

I bought Pacific Audio's CAN/Steering wheel adapter, and no less than five (count'em) antenna adapters. The PAC adapter works, but you don't get illumination or vss, so now I've got to find a way to tie that in to the instrument cluster. Had I gone with the CAN-MULTI I mentioned, I would have been done by now.

I could turn around and sell the PAC adapter so that I could go and buy the soundgate canmulti, but that would involve removing the headunit from the dash ... it took me 4 hours of cramming, cursing, and punching to get it in there considering all the wires jammed into that small area. There's no way in hell I'm ever removing it now that it's in there.

you can tap into the oem sharkfin antenna.

above your rear windshield pull off the trim piece.

there should be 4 fakra connectors:

Blue= gps

red/pink = GSM/Cellphone/Onstar/Telematics

white = sat tuner either xm or sirius(satallite signal)

black = sat tuner either xm or sirius (terrestrial)

the dealer part numbers are measured in meters for length, it is an fakra extension wire:

1M = 000-098-652

2M = 000-098-653

3M = 000-098-654

4M = 000-098-655

5M = 000-098-656

6M = 000-098-657

7M = 000-098-658

the fakra should fit into the sat tuner, if not u can pull it off with a flat head or get a smb connector for the end and plug it in.... i am working on getting the d3 to work with my sharkfin. i will post if/how i got it to work.

VSS is located behind the cluster should be blue w/ white stripe. Make sure you solder and dont cut the VSS wire or you will have problems.