Avantadrive_Original

After searching extensively on various internet forums and Google, my final success for this project came from a tech at a local radio install shop who recommended the part that saved the day. Without his advice, I'd probably still be searching! It wasn't free though... I paid about twice as much for the part as it was actually worth. (I paid $60, you can find the SVEN4 online for $30-40).

I have to modify one thing, so I will take some pictures of the install and add them in here for clarification at some point in the next week.

This is the writeup for how to install a generic aftermarket head unit in an Audi A4 B6 WITH STOCK BOSE AMP, SUB, and SPEAKERS. As usual, I do not accept any liability for this writeup... It is only my advice from my experience, which will hopefully provide a shortcut for people who are confused and lost as I was. Installing an aftermarket head unit really isn't that hard, if you just add one additional part.

<ASIDE...> The head unit I decided to install in my vehicle was the Pioneer AVH-P4000DVD. I chose this because it seems similar to the popular AVIC-D3, but at a fraction of the price, and without Nav. I decidedly do not need Nav in my head unit because I have a TomTom, and prefer a portable device anyway... Frankly, I hardly ever use Nav in day-to-day driving. I did want the DVD feature (mostly so passengers can watch movies during long trips and I can listen), and i wanted to incorporate iPod funcationality in a slicker way than with Blitzsafe and using the iPod as the control, which is the way I've had it for years. I also intend to add the Pioneer XM unit at some point in time, but for now will stick with the XM Commander I have already installed. <>

<u><b>What you will need!</b></u>
- Peripheral SVEN4 (to correct the ground - see explanation below)
- Audi stereo removal tools (cheap on most car audio sites)
- Metra 70-1787 wiring harness, which has RCA connectors
- Head unit with RCA pre-outs
- dash kit of your choosing, head unit dependent (for a double din, the best one I could find was Metra 99-9102).
- Mounting brackets (I did mine custom due to lack of available parts - fabricated L brackets out of aluminum - works fine)
- RCA Connectors, Male, x 4 (any standard 2-channel male-male RCA cable will work)
- Soldering iron, solder, heat shrink tubing


<u><b>Procedure</b></u>

- Note: this procedure involves the proper wiring into the Bose system only - depending on your head unit, you may have additional wiring needs... I'm not addressing those, as that stuff is pretty standard.

1. Remove factory head unit and disconnect harnesses.
- I also removed the climate control module, which just pushes out once the radio's out - just to make things more accessible.

2. Install the Metra Wiring harness power side (the one with fewer pins).
- Note: On mine, this provided constant power and ground, but NOT accessory/ignition power.

3. Wire ignition-switched power: for me, I tapped into an ignition switched fuse that I was already using for my Valentine 1.

4. Peripheral SVEN4 configuration (the tricky part): Here's what I understand to be the basic problem with just plug-and-playing an aftermarket head unit into the A4 with Bose system. According to a pro, the Bose amplifier expects to receive a "Floating Ground" from the head unit, which means the signal from the head unit should not be grounded until after it has been processed by the amp. On my head unit, as with most, the signal is chassis-grounded before it ever reaches the amp. With this setup, the Bose amp picks up every little variation in voltage as felt throughout the chassis, manifesting in a loud POP in all the speakers. As such, we need to conver to a floating ground, which is the primary purpose of the SVEN4 adapter. When I installed my head unit without this, I had a terrible POP sound in the speakers every time sound was interrupted (i.e. changing radio stations or muting the system). With the SVEN4 installed, there isn't even a slight trace of that.

<b>Sub-Procedure for SVEN4:</b>
A. We will be using the provided female RCA harness, which plug into the Metra's male RCA connectors. Plug that in to the Metra harness, and leave it there. You can disregard the spare wired harness provided by the Peripheral SVEN4 makers.

B. We need to convert the other harness, which is wired, into male RCA, so it can easily connect into the pre-outs on the head unit. To do so, snip off the 4 male RCA connectors you purchased and strip the positive and negative from each connector. 4 connectors x 2 wires each = 8 total wires. There are 8 wires (not including the black ground wire) on the harness as well. You see where I'm going with this.

C. Using solder and heat-shrink tubing, connect the positive and negative of each connector to a corresponding positive and negative on the wiring harness. The solid colored wires are positive, and the corresponding color with black stripe is its negative. When you're done, you should have four male RCA connectors, looking similar to the female connectors provided by the company. Make sure these are soldered and protected well, as any defect will interfere with good audio quality. Leave the black ground wire alone.

D. Now, set the two switches on the SVEN4 to "RCA" (NOT WIRED!!).

E. Connect the homemade RCA harness to the "INPUT" side, and the provided female RCA harness to the "OUTPUT" side, which should already be connected to the RCA jacks on the Metra harness.

F. Connect your new male RCA connectors to the RCA outputs on your head unit. Note: On mine, it was confusing as to which channel was which - I simply did trial and error, adjusting the fade/balance on the head unit and changing connections until the proper speakers were activated.

G. Put the cover on the SVEN4 - I taped mine on tight, as the clips were flimsy.

5. Make sure the other Metra connector is attached to the other car stereo harness (on the car side).

6. Connect antenna, accessories, etc. to head unit as you desire. Common examples: You will probably need an antenna adapter, which adaptst the connector AND has a +12V DC lead to power the antenna in the car. You may also want to connect a Dimmer wire, which tells the head unit when the headlights are on, so it dims the screen. I used the blue/gray wire in the back of the headlight switch.

7. That should do it! On my system, the sound quality is FANTASTIC... Initially, I had a bit of background hiss, which I eliminated by adjusting the treble levels down on the system's EQ just a tad... gone now. No distortion at all, and I have fantastic bass.

JeffPGH

Did you change any of the speakers?

Avantadrive_Original

no - everything stock except head unit

CHOUT

Hey

So I am doing this set up now but could I not just connect the wires from the SVEN to my wire harness out of the DIN & set the SVEN to WIRED? I then would not need to use the RCA harness for the Pioneer at all, correct? Take a peek at the photos to see what I am referring to. I did the RCA conversion but now that I look at it, I didn't need to I do not think. Thanks for the write up!





And what about this harness I bought? I understand that the power, ignition, & ground need to be connected but I see the front speaker wires are on that as well. Are those ignored and just connected via the SVEN and the red harness has a blue/white wire. Normally those are for a remote on/off but is this used on an Audi? Cheers!

CHOUT

No one has installed a navigation unit in their Audi here?

borntorage

I am going to do an install soon on my '04. Never saw this info before. I have been searching for a few months now... Here are some links to info I found (nothing speaks to your question):
B6-S4-Pioneer-Avic-Z110BT-Install-Thread
Going-to-install-Pioneer-AVIC-Z110BT-in-B6-A4-3.0Installing-Pioneer-X710BT-into-my-A4
'06 A4 Wiring F700BT
Pioneer-Nav-unit-installed-with-Bose
Ultimate-Avic-d3-double-Din-Navi-dvd-Install-Thread!&highlight=avic+d3+install
Sirius-and-Sharkfin

I plan to call Enfig this week to get some advice. Shops local to me are not experienced in A4 installs with Bose and Sat radio/GPS integration.

CHOUT

Sweet, thanks man for replying! I just finished installing my AVIC-F90BT yesterday and it looks and works perfectly! If you need any help, just let me know. It was a lot easier than I thought it would be.

borntorage

Did your Audi have OEM Sat radio and GPS wiring? I want to integrate into the existing, if present, wiring to use the shark fin antenna instead of runnig two new antennas onto my dash.

Did you do a parking brake bypass in order to leave all features open?