ThunderGrey27OffSuit

I recently picked up a used 96 A4 2.8L that came from the previous owner running a Blaupunkt "Florida" RD-168 headunit. There's two problems that I'm REALLY trying to fix but so far no amount of forum searching has yielded anything helpful. Here's the problems...

1. When I power on the unit there's a pronounced pop from the speakers. This also happens when I: turn off the headunit, switch between inputs (fm, am, cd), and when I change tracks on a CD.

2. The unit isn't receiving constant power, so every time I turn on the car it says 12:00 on the clock and it has conveniently forgotten all my bass/treble settings. Then it pops to let me know it hates me.

I'm fairly sure I have the bose system since the rear deck speakers are labeled Bose. The amp back there looks suspiciously Bose but to be honest I don't remember seeing Bose written on it anywhere.

I need some diagrams of the wiring harness of the Bose system. The diagram on the Blau clearly isn't right since **** doesn't work and the diagram lists colors for things that aren't the same color on the harness. So if someone can tell me what the wires on the harness do I can probably rewire the harness. Any other help would be appreciated also if you know something I clearly don't (and I know little). Thanks!!

MacSub

There's no way round the popping. The Bose amp has a wierd capacitor setup on the input stage, so when an aftermarket HU is being used it grounds the pre-outs to reduce noise when switching between radio & CD (normal behaviour). The Bose amp doesn't like this and the popping is the capacitors discharging very quickly.
to get rid of it you'd need to either replace the HU with an Audi Concert or Symphony, or replace all the Bose speakers and run them off the Blaupunkt HU bypassing the Bose amp.

The wiring problem is a bit easier to sort out. The Audi harness is standard ISO, but they've reversed the permanent live & ignition live. The permanent live is what retains your memory settings. So evertime you take the keys out you're losing everything.
Pull out the HU, unplug the black ISO power plug, cut the Red/white stripe wire (bottom left looking at the wired side), cut the yellow wire/red stripe (3 along from left, top row), and swap them over using terminal blocks or bullet connectors. Make sure these connections are solid & well insulated as they carry permanent power.
Some HU's have a switch on the top to reverse these connections but I'm guessing yours doesn't.
cheers, Andy

ThunderGrey27OffSuit

Now that definitely sucks about the popping/thumping. There was no factory CD deck with the 96 A4 I believe so I'm either looking at keeping the popping aftermarket unit and replacing all the speakers/amp (or trying to figure out an amp bipass), or going back to the factory unit and getting a changer or an iPod connection (and the iPod).

Thanks for the info on the power situation. I'll go out and try that and see if it works. I imagine it should.

Thanks again!

MacSub

I bought a Bose sub for an A3 with an Alpine HU to improve the bass, but the thing kept thudding everytime I switched between radio & CD. Drove me mad, had to swap it out for a JL Audio unit in a custome stealth enclosure, peace at last and hugely clearer punchier bass.
Audi really don't seem to want you to fiddle with their wonderful quality HiFi.
Life was so much easier on my old Golf (Rabbit)