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Walkthrough to replacing your OEM Head Unit (HU) with an aftermarket HU (WRX 08+)

91K views 23 replies 13 participants last post by  fatfreddyscat 
#1 · (Edited)
This walkthrough is designed for someone who would like to replace their OEM HU with a 2-din Aftermarket HU and not tap/cut/splice any factory wires. We will also go over retention of factory USB, AUX, and steering wheel controls.

First things first: Choosing a replacement HU
Finding the right HU for you is essential. In my research, I have come across more people going with Pioneer than any other brand. Doesn't surprise me considering they make some amazing hardware. I personally went with the Pioneer AVH-X5500BHS mainly because it was on sale at the time and has everything I was looking for.

2-DIN JDM Bezel
When replacing the head unit of an 08+ WRX from the stock HU you have two options as far as fittings go.
Usually when you purchase a head unit online you are given the option to also purchase the dash-fitting kit. Unfortunately, on the wrx, the stock HU bezel (the piece that surrounds the HU) leaves a pretty unsightly gap that these dash kits have to fill.

Here is an example of this gap
Electronics Multimedia Vehicle Car Vehicle audio


Now this may not bother some people but if you are like me, you want it to look as clean as possible. The other option you have is to replace the Bezel itself with one made specifically for a 2-DIN stereo. You can purchase this 2-DIN bezels from a select few online dealers but unfortunately none are located in the US. I purchased mine from AVOjdm for around $70 and received it within a week.

Here is a picture showing the difference.
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Picture of what the replacement bezel looks like installed.
Land vehicle Vehicle Car Subaru impreza wrx sti Subaru


Here is a video on how to remove the Bezel and factory head unit from a 08+ WRX


Lets Talk Retention
A lot has been discussed on retaining factory hardware. If you are like me and would rather not mess with any factory wires whatsoever, you pretty much have one option. Hit up SVXdc for the adapters. He is the only name in the game as far as one stop shopping goes for all your Subaru audio needs. Once you know exactly what you need, just shoot him an email with an item list.

USB
To retain USB is kind-of a pain in the ass. It will require you to solder your own wires but it's actually a pretty easy process so don't be scared to tackle it yourself.
Items you will need:
-Soldering Iron/solder
- Hirose Connector (purchase from SVXdc)
- hot glue/ glue gun
- electrical tape
- old USB cable

All you have to do is solder the following (the Hirose connector is labeled 1-4 and the outside is ground.
Connect the end of an old USB cable you cut to the following pins:
1. Black
2. Red
3. Green
4. White
Thanks to MtnXfreeride and his walkthrough and Dan5505's 2013 WRX Build Thread, here are a few pics showing the process.
Take an old USB cable, pretty much any USB cable will work, and cut it about 6-12 inches down. This is what should be inside.
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Solder the wires onto the corresponding number listed above
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Hot glue works best but use something to keep the wires secure and thermal.
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End product.
Water Cable


Now all that's left is to connect the adapter to the end of the stock USB cable and the USB end into the back of your new HU.

AUX
This is the easy one. All you need to do is purchase the pre-made adapter from SVXdc. This adapter can be used with any HU with an RCA AUX connector on the back.
Cable Technology Electronic device Wire Electronics accessory


Steering Wheel Control
To retain your steering control you will need to purchase an adapter that converts the signal from your controls so your new HU can read them.
The only solution for this is to Purchase an ASWC-1 kit.
When you begin to hook up your wiring harness, you will just be adding a few of the wires from the ASXC-1 into the mix.
Here are the direction straight from SVXdc on what wires to attach where. (Do not use the direction that come with the ASWC-1)

2011-up Impreza and Forester with phone buttons (On/Off-Hook and Talk):

ASWC's RED wire to the other RED wires (my harness' and your HU's)
ASWC's BLACK wire to the other BLACK ground wires (my harness' and your HU's)
BROWN/BLACK wire on my 20-pin harness (pin 14) to the other BLACK ground wires (same as above)
ASWC's GREEN/ORANGE wire to the BROWN/RED wire on my 20-pin harness (pin 4)
ASWC's BLACK/GREEN wire to the BROWN/BLUE wire on my 20-pin harness (pin 13)

Do not ground any of the ASWC's other wires.



Wiring Harness

Things you will need:
- Soldering utensils or butt connector
- Crimper/wire stripper
- Electrical tape
- Shrink tubing

If you are purchasing from Crutchfield, they usually throw in the wiring harness and dash kit for free. Thats cool and all but you will be missing some important wires that the ASWC requires to retain steering wheel controls. My suggestion is to purchase the HU from Amazon of something for slightly cheaper and purchase your Harness from SVXdc. His come equipped with all the wires required for connecting the ASWC.
Here is a picture showing the 3 extra wires on the SVXdc harness required to use the ASWC-1
Wire Electrical connector Electronics Electrical wiring Technology


You will have 2 harnesses. One that came with your HU that connects to it, and the other from SVXdc that connects to your stock wiring.
You have 2 options on connecting the wires together. Solder, and Butt connectors. I like solder. I feel it is more durable and easier to work with, but there are people who would disagree. Either way all you will need to do is connect the corresponding colors together and somehow secure the connection.

Keep in mind if you are installing an ASWC-1 you will be adding some additional wires. Make sure before you secure a connection with solder or a butt connector, you double check you have all the wires connected. Once again, here is SVXdc's instructions on installing the ASWC-1
2011-up Impreza and Forester with phone buttons (On/Off-Hook and Talk):

ASWC's RED wire to the other RED wires (my harness' and your HU's)
ASWC's BLACK wire to the other BLACK ground wires (my harness' and your HU's)
BROWN/BLACK wire on my 20-pin harness (pin 14) to the other BLACK ground wires (same as above)
ASWC's GREEN/ORANGE wire to the BROWN/RED wire on my 20-pin harness (pin 4)
ASWC's BLACK/GREEN wire to the BROWN/BLUE wire on my 20-pin harness (pin 13)

Do not ground any of the ASWC's other wires.


Parking Break Bypass (that long ass green wire)
If you are purchasing a DVD capable HU or for some reason you have a super long bright green wire attached to your HU's wiring harness that says "emergency brake" on it, this is a safety precaution that prevents you from accessing some functions on your HU (like playing DVDs while driving and getting too deep into menus) unless the parking break is on. It usually has a vampire clip on the end of it and, once again if you are like me, you refuse to tap into any factory wires. Luckily the make little micro Parking Brake Override Bypass units that you wire directly to one of the harnesses.
Cable Technology Electronic device Electronics accessory

These are model specific so make sure you get one that corresponds to your HU's model.
This thing is simple to hook up but keep in mind, you will be adding these wires into the mix of other wires when connecting your harnesses together. Don't forget to double/triple check when it has come time to hook it up. Unlike the ASWC-1 you CAN use the directions that come with it.

Bluetooth Mic
Unfortunately, as of right now there isn't a method to retaining the factory bluetooth microphone. There are a few threads of people attempting to solve the problem however.

Most HUs come with their own bluetooth mic. Many threads have been started on finding the best spot to put it.
There was one person who briefly popped into a forum saying he routed it to where the factory mic is located (middle of the dome lights), moved the factory mic out of the way, and used some double sided sticky foam to adhere it in place. At some point I hope to attempt this and eventually update with a quick walkthrough.

(UPDATE) Just finished a walkthrough on replacing the factory Bluetooth mic with your new mic in the factory location. Check it out here!


Overview and parts list

Items to request form SVXdc (order info page: scroll down for e-mail address)
- 20-pin harness
- AUX adapter
- USB connector
Other items
- AVOjdm 2-din Bezel
- Parking Brake Override Bypass (look up by model number of your head unit on amazon)
- ASWC-1 (can also purchase from SVXdc or Amazon)
- Tools for soldering or butt connectors


Thats it. Thats all the info you should need to replace your head unit and retain all your factory goodies (other than bluetooth)


- oOTAGOo
 
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#4 ·
Yes I did keep my factory speakers. There was a noticeable difference in sound quality and for the most part just having an HU with an equalizer helps dramatically. In reality though, adding a sub was what made the most difference. Though it was a pain in the ass to pull up all the trim and run the power cables through the firewall, it was totally worth it.
 
#5 ·
Awesome walkthrough. Wish this was around a year ago so I didn't have 3 windows open trying to figure it all out! Also most headunits these days accept USB on the backend and sometimes come with a long usb cable. I ran mine along the center console area and between the seats
 
#12 ·
Hey there sorry for such a late reply but yes, I did actually just install the nav extension. Turns out it comes with 2 antennas, one for the GPS and one for the traffic notifications. I originally tried to mount to the top of the HU like others have mentioned but found it a little tight and didnt want it to get ripped off if I ever had to remove the HU for any reason.

What I actually ended up doing was mounting both antennas BEHIND the HU on top of what I believe is some of the air ducting. It's my understanding that you can mount these to damn near anything under your dash as long as there isn't any metal or really thick plastic above them to block the signal.

I have had no issues with GPS or traffic signals since I installed it in December so I totally recommend trying it out.

Just an all around update: Still no problems with anything on this HU setup. Only have good things to say about this install.
 
#16 ·
I used this writeup, as well as a few others and I also had great results. One thing that took me too long to figure out was that if using the JDM bezel, you don't need to purchase any sort of mounting hardware. You simply reuse the factory brackets with the Pioneer screws.

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#18 ·
HELP! I bought the navi unit off of ebay and I want to get it installed however, unfortunately, it seems as though SVXdc (at Subaru radio and radio wiring harness information) doesn't respond to emails and so I don't know how to obtain the remaining harnesses short of making them myself (which I would have no clue about, unfortunately). Can anyone give a tip as to how to go about getting it installed (I just don't trust myself to do it myself)? My hope was to just buy all the necessary harnesses and then take them to the installer with this walkthrough but now I can't get the harnesses... please help?
 
#19 ·
Just give him time its a side business. You can get the generic harness for a temporary set up though it does not have wires for the steering wheel control
 
#21 ·


Its not complete so you will not have steering wheel controls and some.others basic power speaker etc with be there

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#22 ·
Darn, I wasn't clear, I'm so sorry -> I have a 2014 WRX Hatch with the vanilla, generic stereo head unit and I purchased a navi head unit and want to install the navigation head unit. Any idea if this "2008-2011" would fit the navi head unit? Or, do you know of/where to get a harness for my model?
 
#23 ·
It should fit just fine again this would be a temp fix just to get the stereo working I Forget exactly which pins it missing but just refer to AE64 for the wiring diagram
 
#24 ·
I just want anyone that comes across this to know that I *did*, in fact, get in touch with, purchase, receive from, and successfully had professionally installed the adapter harnesses from ae64.com as well as the rear view camera (purchased off a guy on craigslist), and oem (from a brz) navi head unit (in addition to amps under the seats, dynamat, infiniti speakers and a 15" jbl sub). And I am forever grateful and happy!!!
 
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