2005 Subaru Aux-in Hacking


The CD player in [mukmuk’s] 2005 Subaru Outback gave up the ghost, and faced with a long road trip ahead of him, he was desperate to find a way to listen to something other than static-filled radio. He considered a 3rd party auxiliary input solution, but after seeing a similar aux-in hack here, he figured he could give it a go himself.

The stereo head unit design was changed between the 2004 and 2005 model years, so while he had a good idea of what to look for, he had to find the proper components on his own. Once he identified the radio module, he was able to locate the left an right input pins through trial and error. He carefully soldered a 3.5” audio jack to the head unit’s input lines, wiring it to cut off the audio signal from the radio whenever his Zune was plugged in.

Everything was reassembled, and the input jack was inconspicuously mounted in a cubby hole just above the stereo. [mukmuk] is quite happy with his modification, and we’re guessing his road trip was far more pleasurable as a result of his work.

32 thoughts on “2005 Subaru Aux-in Hacking

  1. FM transmitter is OK for local use but on a long journey, sods laws says that the vacant frequency that you are using will be occupied when you get to the next city.
    So, you have to manually tune the radio to a fresh vacant slot then retune the transmitter to suit. This normally happens in busy traffic!

  2. Honestly, FM transmitters never worked all that well for me in my area. It could be that we have a pretty congested FM band, but I always got interference, and the sound quality was never great.

    Once I got my iPod hardwired into my car, I ditched the FM transmitter right away.

  3. I have an 05 subie, so this hack is relevant to me. I’ve been eyeing that 3rd party piece, but now I may have the guts to do it myself.

    @biozz Where I live, nearly every radio station is taken, so my music through the FM transmitter is always filled with static.

  4. @clinton dont even hesitate, did this years ago after seeing an instruction set for similar input to a pioneer headunit which had a proprietary connector on back. I drive an ’05 Impreza 2.5RS however, and my headunit looks to be diff. than the one posted.

    All the same, some spare pin receptacles from the front panel hookups of an old PC case worked perfectly for whipping up my own custom pin-out adapter, they fit snug right on the pins, good luck.

  5. This is something everybody should do even if your CD player isn’t bad. My 97 Maxima doesn’t have an aux jack but I’ve been using a cassette adapter that works well for now.

    The FM transmitters are all complete garbage if you value sound quality. They sound like listening to music through a tin can with a blanket over it.

  6. After seeing that same post, I also took my radio apart. I have a similar 6-cd changer similar to this one. It consists of one main board, and the cd changer part has a ribbon cable that plugs into the main board. I opted for an aftermarket board that wedges between the ribbon cable and the socket it plugs into. It offers 2 rca jacks. I ran a rca cable out the back, and fished it through the AC vent. I have a blank CD in the changer, and just select it when I want to use the aux.

    In my case, I am using my Droid. I JB-Welded the phone dock piece of a suction cup mount to the AC vent panel (yes lads, hard core), and added a USB cable for power. It also goes through the vent, behind the bezel and into the cigarette lighter, which holds a USB power adapter.

    I kept my cables neat- 90 degree connectors, and they protrude just enough to reach the mount. Unfortunately, even with a ferrous core shunt on the USB cable, it is noisy. But it is very handy to have now that I am using my phone more often.

    The phone also works as a speaker phone now, but I have to have the AC turned down. My kids and I watch Regular Show while waiting for the school bus.

    1. please tell me you encourage them the get ready by saying something along the lines of “if you’re quick, we’ll have enough time to watch a WHOLE episode!”

  7. Have done this or simular in a few different cars. I encourage anyone attempting this to make google your friend. By googleing what your attempting to do, you’ll more than likely find multiple well put together instruction posts (like this one) on various enthusiast blogs for your car. You usually do not need to sign up to view and by looking at few different examples, you’ll more than likely get tip one might have left out from another. I’ve found going this route to be very helpful in modifying anything in the car. One tip I’d like to add, it take a picture of the wiring set up before you start. That way if something doesn’t work, you can always go back to stock and try again. Good Luck and have fun.

  8. Good work with the 3.5mm jack. I did a similar hack a few weeks ago, but on the CD audio signal lines. Some of my pics are available at http://www.suzuki-forums.com/suzuki-aerio-liana-forum/45490-2003-aerio-clarion-stereo-aux.html#post279761

    Although I anticipated needing one, I do not have to use a silent CD. However, charging my mp3 player from car power gives an unpleasant hum on the speakers. Perhaps it’s because I used one ground trace(CD_GND) instead of another(S_GND).

    It’s a very easy addition to a car stereo in my opinion. If you were on the fence, dive in and you may be surprised.

  9. Look how large the radio CD changer is! The front controls are on a separate circuit board as well.
    Make me wonder about a hack involving a gummstix, harddrive, and such. Sweet.

  10. Good work with the 3.5mm jack. I did a similar hack a few weeks ago, but on the CD audio signal lines. Although I anticipated needing one, I do not have to use a silent CD. However, charging my mp3 player from car power gives an unpleasant hum on the speakers. Perhaps it’s because I used one ground trace(CD_GND) instead of another(S_GND).

    It’s a very easy addition to a car stereo in my opinion. If you were on the fence, dive in and you may be surprised.

  11. Do those Subaru headunits have “surround” capabilities? Like having 4 channels (obviously for FR, FL and RR and RL). Especially if this difference is already “accessible” at the input side? I’m thinking of getting myself a 2007/2008 Subaru Impreza (not the new toy car…the previous model…for reference, see “ken block gymkhana 1” on youtube) and also thinking about hacking in a carputer.

    Or do those things just use one stereo line which is sent to Front and Rear equally?

  12. I did a similar project on a blaupunkt head unit in my old car. It worked in the sense that I could hear my external source (iPhone) however the line level was way too weak for it to be enjoyable. A friend said that the head unit’s aux in was probably designed to pair w a blaupunkt cd changer, which would have had a built-in preamp to provide suitable line levels. The output levels on my iPhone are plenty loud enough for headphones/small speakers, so why did the signal drop so low when piped into the head unit? I even reduced my wire lengths (had a 8′ cable to allow for backseat djs) thinking the inherent resistance for such a length may have been the cause, but still no joy. I’m about to try the same thing w my 1999 Mazda truck w factory head unit (same as ford ranger and many other autos I’m sure) but don’t want to have the same result. As far as fm tx goes, i instantly returned my 90$ buy because of all the aforementioned reasons plus the clutter.

  13. I for one am glad fartface is here. I agree that it is far better to buy a nearly $50 FM transmitter that needs to be wired up and hidden somewhere in the dash. I mean why buy a $1 jack and wire up an aux jack yourself? That is just plain dumb!

  14. @fartface

    FYI that’s not really an FM transmitter, that’s a wired FM modulator and it would require nearly as much as work as this hack, plus it would cost a ton more. And even after all that money you’re still just listening to FM so your sound quality is not nearly as good as plugging directly in like this hack. Besides, you’re pretty lazy if you would rather spend $50 on a $0.05 fix.

  15. TBX to Mukmuk for recording, posting his project to help those who would find it helpful. I’m another who is wondering why he didn’t elect to go through the dead CD player rather that futz with a functioning part of the unit. My vehicle is old enough it has a factory cassette, instead of a CD player. So I’ll be using a cassette adapter for any portable CD or mp3 player. In the event the truck lacked that I would have elected to build build an FM “transmitter” that would be inserted in the antenna feed line. Now I’d elect to buy the audiovox unit, I’m no longer compelled to DIY everything. As I no longer take roads trip long enough that using recorded tunes becomes nice, I’m likely to do nothing in this direction.

    1. If anyone wants to know how to add aux to a 2006 Toyota Camry, send me an email. -Dan

      Just acquired a 2005 Toyota Camry and its Toyota radio/cd-player 16860. Nice car but the adding an audio aux jack will be the second modification, right after adding a second surface mount 12vdc power tap. I’ve reviewed the factory service manuals for how to tear apart the center instrument cluster and a bit of the wiring. Pulling it apart to examine the radio is the next step.

      I don’t see an email link for you, Dan, so hoping that a reply might make it. Would love to have more information on how you managed. Thank You.

  16. Did it in 1970, is my dads Olds, some things never change. This is the way to go! Original source must be cut, no blank CD’s. Just use HiFi sources, not distorted crap. Most of what people are hearing with FM xmitters is caused by digital crap. The isolation transformer can be taken from a old answering machine or cordless phone, and will clean up hum and whine. 2 are needed.

  17. Hi, happy my hack was featured here! Just got back from my road trip and it worked great, the only problem was a bit of a high pitched whine (as mentioned in the comments above) when either the Zune or iPhone was plugged into the 12v inverter. I’ll look into installing some sort of isolation transformer system as suggested, but for now it isn’t that bad and I can just make sure my devices are charged before hooking them up if I want that crystal clear sound :)

    Oh, and the reason I didn’t want to interface from the broken CD unit is that it doesn’t activate the sound output until a disc is actually playing. The CD unit won’t play any discs, it just ejects them after a few seconds of trying to read.

  18. My gf has a 2004 GMC Envoy SLT, and I know there must be way to add aux to it. I did it on my aftermarket Alpine face by hooking up a switch to it. I don’t have to have a blank CD in it either. The face just says intrrpt permanently, which is fine, and all I do is flip the switch to use CDs which is barely ever.

    Has anyone ever added aux to an Envoy? It has a 6 disc one slot CD changer in the face if that helps. Much appreciated.

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