DIY: B6 A4 - Aftermarket double din head unit installation w/ pics

[lookaught]

This DIY covers the install of a Pioneer AVH-X3600 double din head unit. The DIY should be pretty universal no matter what brand or model you choose. I chose Pioneer because I have a similar unit in my truck, and am familiar with the interface. I picked the 3600 because it does not have a motorized faceplate, I just wanted functionality of bluetooth and good equalizing for sound quality and phone calls.

I never wanted RNS-E and after nearly 8 years of owning my B6, it's time to get some hands free calling and some streaming bluetooth music.

Step by step in full color!

Bottom line: Very easy install, $316 total cost, add $60 if you want SiriusXM (I didn't).

Teaser pics:




The DIY is split up into two posts: this post covers the prep done inside your house, the second is the actual installation in the car.

Required tools:
-Radio keys
-8mm socket with various extensions
-10mm box wrench for the battery
-pliers
-electricians pliers
-a plastic pry tool is helpful
-electrical tape
-patience.

I purchased my head unit from Crutchfield. The reason is simple: good prices, outstanding technical support, and they throw in for free all the odds and ends needed to install the unit, such as harness adapters, antenna adapter, faceplate, etc.

For a B6, you need:
-the head unit
-Metra 40-VW54 Antenna Adapter
-Metra 70-1787 Receiver Wiring Harness
-Metra 86-9001 Factory Radio Removal Tools
-Metra 99-9107B Dash Kit
-PAC SNI-1 interference filter (one if you have a normal stereo, two if your car has factory Bose)
-one pack of Posi-Products Car Stereo Connectors (BUY THESE, don't solder or use crimp connectors)
-one fuse tap
-one 18-22 gauge wire tap.


Ok, time to get wiring:

First, start by determining whether your car has factory Bose or not. I thought mine did, as it turns out, Symphony is not Bose, so this DIY shows how to wire both. Factory Bose says Bose on the radio. Simple stuff.

When you're in your car figuring this out, remove the CDs from the stock radio. If you don't, you'll be stuck like me jamming a wire from a battery into the radio on your workbench to power it to get them out.

Ok, first, pull out all the harnesses and lay them out. You should have a harness for your head unit:


And you’ll also have two harnesses in the metra kit, plus the antenna adapter and the RCA filter(s).


The faceplate with the single din support still attached:


And the posi connectors:


A wiring diagram for 2005 and up cars:


And for 2002-2004 cars, like mine:



Time to wire:

Take the harness from your head unit and look up what each wire is in the manual. Generally speaking, there will be:
-Constant power (yellow)
-switched power (red)
-antenna power (blue)
-illumination switch (orange)
-ground (black)
-speaker outputs for the front speakers (gray and white, the grounds have stripes)

The Metra harness has all of these as well. Refer to the diagrams for each wire, but the colors are all pretty standardized.

So, match them up and start connecting them with the posi connectors: yellow to yellow, orange to orange, black to black. The only odd ones are:
-The blue wire on the black plastic Metra harness is NOT connected to anything. Tape it off. Instead, three way wire the blue wire from the head unit harness to the red metra harness, and the antenna adapter. (see photo below)
-for 2002-2004 cars, you must run a switched power to the fuse panel. This longer wire is included in the kit, but don’t bother connecting it to the head unit harness yet, as you must snake it under the steering column to the fuse panel first. (it is connected in the pic).


Bose vs non-Bose speaker wiring:

Non-bose cars power the front speakers through an internal amp in the stock head unit. You must connect the gray and white wires on the metra harness to the front speaker output wires on your head unit harness if you have a non-Bose car. The rear speakers use preamp outputs, so you will need to use the RCA filter and the rear speaker outputs on your head unit. In other words: directly wire the gray and white wires for the front speakers, then use RCA and one filter for the rears.

Bose cars use preamp outputs for ALL speakers, meaning that you do NOT wire any speakers directly to the head unit, instead, you use the RCA outputs on your head unit, with in line filters for BOTH front and back.

Close up of the metra harness with the non-Bose front speaker wires:


Close up on the Pioneer harness. Notice the gray and white wires, those are what you connect. The green and violet wires are for rear speakers, but in all B6 cars the rear speakers are powered by an external amp, so tape those off.


This is how it looks when wired for a non-Bose car:


This is how it should be taped off if you have Bose. Each wire capped off individually, then taped into a bundle:


Bose harness, ready to go:


Notice that there are additional wires on your head unit harness. The green is the parking brake ground switch that must be wired later to allow you to play DVDs and to set up Bluetooth connections. The purple is a rear view camera switch, which is used if you wire a camera.

Head unit prep:

The Metra kit must be prepared for the head unit, first by removing the center bar that is used only for single din installs. I used a sawzall blade:


Use the larger plates for a double din, discard the smaller ones:


Snap the plates (I use “snap” loosely here, they really just sit in the groove along the faceplate once the center bar is removed. Then slide in the head unit, snap in the thin plastic surround on the front, and attach the head unit with three screws per side. Depending on your head unit the screws might be in different spots:



Now, out to the car!

[lookaught]

Installation in the car:

First, DISCONNECT THE BATTERY NEGATIVE

Start by removing the fuse panel cover and the cover on the passenger side of the car with a pry tool.

Next remove the kick panel under the steering column. There are three bolts: one behind the fuse panel cover, two underneath. All are 8mm. Once removed, pull the panel straight back toward the rear to disengage the tabs that are below the belt line trim, and wiggle it out. You must disconnect the OBD port and the lighting.

Also remove the glovebox. For some reason, Audi chose to attach the glovebox with military IED grade bolting. There are total of nine 8mm bolts: two or three underneath, and I think 7 inside the glovebox. Beware that once they are removed the glovebox will fall, so I suggest removing the center bolt inside the glovebox last.

No glovebox


Next, remove the radio. Insert the keys with the point on the outside, and the rounded parts facing inwards. I forgot to take a photo of key you use but it’s the rounded one. Google Audi radio keys and you’ll see what they look like.

The secret to removing the radio is to move one side at a time, do NOT just pull straight out. Right side out a little, left side out a little, repeat. One it’s out, disconnect the three harnesses and the antenna, and there is a small fourth antenna looking connector that you disconnect and never reuse.


What it should look like when the radio is out. The antenna is tucked out of sight:


Wire the microphone: I opted to put it above the rear view mirror, and ran the wire under the headliner to the passenger side A pillar, and down. Use your plastic pry tool if you have one to push it into the trim:


Photo just before I tucked the wire away:


Then just run it along the underside of the dash and you’ll end up with some extra wire to bundle up:


Next, run the switched power from the radio cavity, under the steering wheel and snake it to the fuse panel. No pics of this, sorry. This is why you don’t connect this long red wire to the harness in the house, it’s kind of a pain to snake it. Tap the end into fuse #36 with a fuse tap. I STRONGLY SUGGEST that you buy proper fuse taps, the one in the Metra kit is garbage. Don’t forget to attach the other end to the red wire on the head unit harness with a posi connector.

This photo is from before I tapped #36. I have other things tapped as well, your stock fuse panel will have no other wires or taps like mine.


At this point, I noticed it was past noon. So:


Refreshed, start plugging in the harness you made. It’s plug and play for the most part, and the harnesses are molded so that you cannot reverse them. Two plug into the black Metra adapter, one is for the RCA preouts in the red Metra adapter, and then the antenna.


If you have a Bose car, it will look like so, with two filters. You do not need to ground the brown wires. If you have a non-Bose car, only one filter and it will be connected to the green and violet RCAs.


Put a towel down over the center console to avoid scratches, and start plugging in the head unit. For non-Bose, there will only be one set of RCAs plugged into the rear speaker preouts. This is a photo of a Bose car setup. Also plug in the antenna adapter, and the microphone.


It should look like so:


Reconnect the battery, turn the key, and power it up!


It will be a jumbled mess:


At this point, test everything. Power, each speaker, make sure the unit dims when you turn on the vehicle lights, ground out the parking brake cable and test the DVD and Bluetooth, and test the antenna by using FM radio. Make a hand free phone call, stream some music, etc.

When you are confident that everything is working, wiggle the radio into place, reach through the glove box side and push wires out of the way, etc.


Ignore how the green wire is attached here, this was how it was grounded before I realized Pioneer has a smart head unit and you can't simply ground it out, it must be switched to the parking brake. This photo is to show how the wiring looms looked with the radio fully in place.


THIS IS THE POINT OF NO (easy) RETURN. The Metra kit is very difficult to remove because it snaps into place. To remove it once it is seated you have to take out the glovebox and kick panel and pry up the retaining tabs from behind. So make sure everything works and looks good, with no binding etc. also, snake the green parking brake wire out the glove box side.


I tucked the wire up along the transmission tunnel and pulled it to the parking brake switch. It is in front of the rear ashtray. To remove the ash tray and heated seats switches (if your car has rear heated seats), just pull.

Use a 18-22 gauge wire tap and tap the striped brown wire on the parking brake switch. Double check this works by engaging and disengaging the parking brake with the radio on, it should enable and disable the Bluetooth connectivity options panel, as well as the DVD image. These functions should only work with the parking brake on. Companies do make bypasses for the parking brake switch, and I think that Clarion head units only require grounding of the green wire to disable the safety of the handbrake. YMMV. I don’t watch DVDs while driving, so I just installed it as intended. FYI I believe it is a federal crime to disable the parking brake switch to allow you to watch video while driving, so do so at your own risk.


Reinstall the rear switches and ashtray, make sure all wiring is tucked away.

Reinstall the glove box and driver’s side kick panel. Don't forget the two tabs that are up by the pedals on the driver's kick panel.

Adjust the display and illumination to match the Audi red.

Equalize the sound as you see fit. I found that I needed to move the balance pretty heavily toward the rear to equalize the speaker levels.

And enjoy your new stereo!

[lookaught]

DIY is now done. Comments and corrections are appreciated.

No comments about the dog hair and sand in the car YFFs! I know it's dirty. But i just spent 2 hours of my Saturday writing this DIY, I have no time to vacuum.

[lookaught]

For some reason edit isnt working...

Update: the illumination wire which is designed to let the unit know when to dim by providing a 12v signal when the lights come one does not work. I pulled the glovebox and tested the orange wire and it had no voltage. With the Metra faceplate it's pretty much impossible to remove the radio without breaking the faceplate, so double check the illumination wire before you snap it all into place. I managed to get access to the wire from the glove box side with the radio still installed (major headache) and then wired it directly to the headlight switch. To do this, remove the headlight switch and the panel below the steering wheel. Tap the gray/blue wire on the left side of the headlight switch harness with an 18-22 gauge wire tap and connect that to the orange wire on your head unit pigtail. Verify it gets 12v when the switch is turned on.

Regarding the Metra kit and the poor design that makes it impossible to remove, that is a major frustration. However, I dont think it should discourage anyone from doing this upgrade, as the metra kit comes free with your head unit if you buy from crutchfield. If you have to remove it and you break the faceplate, another company called enfig makes a nice replacement: http://enfigcarstereo.com/ENFIG_RMK8_A4B67.html. A good option for $50

[lookaught]

Update:

So for a number of reasons I have to just recommend the Enfig kit. It's expensive: $50 for a face plate and cage, $100 for a harness to fix the low rear audio, and $20 for the plug and play adapter for the head unit, but it is worth the money. I used the Metra kit because it came free with my radio, but don't waste your time.

The reasons: First there is the low rear speakers and sub problem that I believe is caused by a low voltage from the pioneer head unit, the Audi head unit must preamp the signal to the amp at a much higher than normal voltage. I initially thought I'd just upgrade the amp to a Soundstream Picasso Nano, but after doing a full blown custom install on my dad's Mercedes SL (head unit, amp, wiring, custom harnesses....) I decided to just try the plug and play and stick to a simple solution. The Enfig smart harness is really impressive. Not only does it fix the low rear audio problems, it also somehow knows when the lights turn out without a standard illumination wire, and no need to run a switched wire to the fuse box. The plug and play adapter for the Pioneer also reverses the normal wiring and powers the unit from the switched power, which is actually quite nice as you can fully turn off the car and key, but the radio stays on until the key is removed. Simplicity was also nice. I only had to cut and connect one wire: the power wire for the antenna but only because I didn't buy the Enfig antenna I reused the one I had. Finally, the faceplate and cage are a big improvement. Removeable, better fit, standard removal keys... it's a nice system and looks good. The Metra kit was a PITA to get out.

So, save yourself some time and hassle and just buy the enfig products. They are really convenient even if they are a little pricy. My only gripe is that the Enfig plug and play harness didn't fit in the head unit well, somehow the power and ground wires didn't line up with the pins on the head unit and the wires popped out. I fixed this with epoxy for the time being and will talk to enfig about a replacement.

Oh, and normal shipping was free, and it was still sent Priority Mail and made it to me in three days (and I live in the middle of nowhere, Wyoming).

I hope this helps someone in the future. The upgrade was huge and now that it all functions properly, definitely worth the ~$450 it cost.

[cole_sanders13]

This is an amazing write up! Just wanted to say thank you, this helped me a TON.


Sent from my iPhone using Audizine

[lookaught]

This is an amazing write up! Just wanted to say thank you, this helped me a TON.


Sent from my iPhone using Audizine

Glad it helped out!


Jon

[g8erfan1982]

DIY is now done. Comments and corrections are appreciated.

No comments about the dog hair and sand in the car YFFs! I know it's dirty. But i just spent 2 hours of my Saturday writing this DIY, I have no time to vacuum.

Were you able to get your factory Bose sub to work using that wire harness kit?

[BumblebVR6]

I've done this same install in my '05. It can be a PITA. I installed a compact Alpine amp into the glove box to power the highs, as well as a sub amp in the trunk. Had to figure out (with the help of Crutchfield) which wires to cut and splice at the factory amp connector in the trunk. I used the Metra kit as well and just shaved down the retaining tabs down a bit. Doesn't lock into place, but makes removal easier if needed. Great write up.

[Anthony k]

Very nice write up.


You Audi guys are rally good at these

[lookaught]

Were you able to get your factory Bose sub to work using that wire harness kit?

The enfig harness?

[g8erfan1982]

No, the one from your original post using the fuse tap.