Introduction: Add an Auxiliary (MP3/Ipod) Input to Your Car's Stock Radio

Picture of Add an Auxiliary (MP3/Ipod) Input to Your Car's Stock Radio

So you've got this great little MP3 player or Ipod, but your old-school car only has a CD changer? Sure you can get an FM modulator, but they don't work so great and are notorious for poor sound quality. I decided to leverage the CD player in my car to add a CD-quality auxiliary input for my MP3 player.

What you need:

-- Stock car stereo with a CD changer input
-- Basic Soldering Skills
-- Soldering Iron & Solder
-- Hand held Volt/Multimeter (to find right wires)
-- Small gauge speaker wire (anything around 18-14 gauge will work)
-- 2 panel mount 1/8" stereo phone jacks ($2.99 for 2 at Radio shack)
-- 1/8" stereo plug cable ($5.99 at Radio Shack)
-- Old pair of headphones (really just need the wire & 1/8" plug)

Essentially what you are doing is sending a pirated signal from the MP3 player onto the line that would normally be sending audio from the CD changer. In order to prevent a mixing of the audio from the changer & your new pirate Aux input, you have to play a special CD which contains tracks with perfect silence. It may sound complex, but is quite simple with some basic electronics/soldering skills.

Step 1: Remove Your Stock Radio From the Car

Picture of Remove Your Stock Radio From the Car

This is probably the biggest challenge in the whole project. If you do any work on cars, then your shop manual will help, but also there's tons of user forums dedicated to specific car models. Google around a bit and you should be able to find tips & help.

You may also try calling local car audio shops and ask them for tips on how to remove the radio from your specific make/model. Most are moderately friendly and will give you tips, just don't expect them to come do it for free or anything.

Step 2: Locate the CD Changer Plug & Pins

Picture of Locate the CD Changer Plug & Pins

Locate the CD changer plug and gain access to the pins for audio transmission from CD changer to head unit. It should be something like the socket below in the lower right hand corner. They usually have about 8 or so pins arranged in a circle.

Now here's where you have to do a bit of googling. Figure out what the pin layout is for your radio's CD changer. Try searching with something like "Honda Accord 1996 CD changer pinout" I was able to find this layout for an Acura which was close to my Honda for the basis of mine. Remember, there's only a couple car makers, so there's a lot of similar equipment out there across brands. Honda Civic may be close to the Accord, and also close to an Acura. The same should apply for domestic cars made by the same manufacturer.

The 3 pins you need are:
Signal Ground
Left Channel
Right Channel

Step 3: Solder in Aux Input Jack

Picture of Solder in Aux Input Jack

Once you have identified the audio pins, find a place to mount the internal jack. Using short pieces of small gauge wire, solder connections from the pins on the stereo to the pins on your panel mount 1/8" audio jack. Be sure to keep the signals correctly matched to the right pins so you don't end up crossing channels or ground.

Step 4: Mount the External Jack in Dash

Picture of Mount the External Jack in Dash

Now that you have the internal jack mounted & wired, find a nice location in the dash where you will mount the external jack to plug in your MP3 player. Carefully drill a hole in the dash just larger than the jack to mount the external jack.

Use the old headphone cable and cut to the appropriate length to connect the internal and external jacks. Plug the cable into the internal jack, and solder the wire ends to the external jack. Take caution to match the pins (refer to plug layout diagram if needed) This cable serves as the quick-disconnect patch cable, should you need to remove your stereo or take apart your dash in the future. Soldering directly without this patch cable could be a pain later if you ever need to remove the dash or stereo for repairs, etc.

When drilling in the dash, be very careful and know exactly what's behind your drill bit so you don't accidentally drill into something important!

On mine, I had a spacer/junk bin that was right below the radio. This made an excellent location to mount the external jack since it was inconspicuous and also I could wire it up at my workbench instead of in the car. Choose the location you like best to mount the jack. Push the jack through your hole you drilled and use the nut supplied with the jack to screw onto the jack and hold it in place.

Step 5: Test Your Connections & Reinstall the Radio.

Picture of Test Your Connections & Reinstall the Radio.

I'd suggest a test run before you completely reinstall the stereo to find it doesn't work. Hook up the cables and give it a try. If everything sounds good, install the radio and put the dash back together.

Once it's all together, all you have to do is put the CD changer on your "silent" CD, put it on track repeat and use the MP3 player to pump the tunes.

You can see here's my setup with the jack installed. Sleek and WAY better than an FM transmitter.

Step 6: Burn Your Special "Silent" CD

Picture of Burn Your Special "Silent" CD

Now, in order to play the audio from your MP3 player, we need to trick the CD changer into thinking it's playing a CD. The stereo doesn't know that the audio is really being supplied by your MP3 player instead of the CD changer.

In order to do this we just burn a special "silent" CD. It's got regular tracks, but there's no sound played. Download the 5 minute "silent" MP3 below and create a CD using your favorite CD burning software. I took the same file and added it multiple times to the CD so that I had many tracks. Just fill up the CD with these blank 5 minute tracks so even if you don't have the CD on repeat, you'll still hear nothing from the CD and everything from the MP3 player.

Once you've burned the CD, pop it in your changer, put it on repeat play, and you're all set. Turn on your MP3 player and test it out.

At a cost of under $10 and 1-2 hours (depending mostly on how easily you can get your radio out of the dash) it is well worth the great audio you'll now enjoy!


teamtunell313 (author)2017-02-01

Did this for a 2006 Suzuki Aerio. It has a 6 CD changer feeding down to the radio/amp via a ribbon. So, we downloaded the parts manual for the CD/AMP combo, determined which pins were the CD signal pins, and soldered 26 Gauge wire to the ribbon connector pins (Braided the wires, but I wish we had just twisted all 3 together with the drill). It actually worked really smoothly except I burned the blank file to a DVD+R disk instead of a CD. We struggled with that problem for about an hour! Crystal clear audio, perfect volume, and no engine hum. Thank you Thighmaster!

SurfingSi (author)2016-09-12

What a great idea. Head Units have moved on. Mine now has Bluetooth and 2 x AUX inputs (front and rear). But I still use CDs. I want to carry on using my CD Changer. How would I do a revers of this? That is, use the rear AUX input for the CD Changer? Guidance from someone who can figure this out very welcome!. Also, instead of solder, thought I'd use electric glue - I'm sure there must be some these days?

SaxyOmega90125 (author)SurfingSi2016-10-13

aka_bigred is right, sort of. There is no easy, permanent way to do what you suggest. I assume you still use CDs because of the sound quality - I can't think of any other reason - so I see two options.

The first is to use a decent portable CD player that can use a DC charger. If you want to make this somewhat more permanent and safer I'm sure you can figure out a way to mount it somewhere in your car, although if you want it to look good too you might have to get creative.

The second is to rip your CD collection and use the files. If you go this route, I would recommend using a program called Exact Audio Copy to rip them as FLAC - if you're going to do something, do it right, and as a bonus even if you don't play them these files can be kept as a full-fledged archive for future use - and then use another program to copy and convert to mp3 en masse later if necessary. You can find more info on doing this sort of thing online. Then, play the files with an iPod Classic or some other portable player with a decent DAC (ie *not* most phones).

aka_bigred (author)SurfingSi2016-10-12

You likely can't easily do what you suggest, unless your head unit already supports your CD changer.

This instructable allows you to "trick" the OEM radio into playing your MP3 audio as if it came from the CD changer. What you describe would need the head unit to interface/communicate with a different CD changer that is wasn't designed to work with. Unless your head unit is compatible with your old CD changer, I think you're out of luck, or need to find some specialty interface to allow it to communicate with an OEM changer. Unfortunately, that's a completely different animal that what I've done here.

FYI - they do make "wire glue" but I've never used it and wouldn't trust it to something installed into a relatively harsh, inaccessible environment like a car. You want the best, most permanent connection you can make, because if it comes loose 1) you'll have to pull apart the dash again to fix it, and 2) you might accidentally short out something else important if a wire's just loose & flapping around as you drive down a bumpy road. Wire glue might work elsewhere in a pinch, but you'd have a much better connection, and also have a very useful skill for the future if you lean to solder.

inventorjack (author)2007-11-15

I'm sitting here and wondering why I never came up with this awesome idea. Great stuff! Thanks for sharing!

IlyaG (author)inventorjack2015-12-20

Hey... so i did this in my jeep and everything works.. except I hear engine whine when playing anything through aux jack.. any ideas?

DaniM34 (author)IlyaG2016-08-14

Had the same issue. It's your ground. Try finding a better spot or cheking your solder joints.

TqW (author)IlyaG2016-06-02

this is due to the cable your are using is not good quality coaxial cable, try replace this cable from a multimedia speaker input cable, these noise will go.

iungerich1 (author)2015-12-12

could this be done without the cd changer unit? i have the head unit with the cd changer input pins but not the changer it self

RadBear (author)2007-11-16

Can you do this w/ a single disc CD player?

aka_bigred (author)RadBear2007-11-16

Probably not - the whole hinge point to this project is the accessibility to the CD changer input pins. I'd guess that on a standard stereo without a CD changer, these pins are all internal and accessing them would require completely dismantling the radio.

gohenderson (author)aka_bigred2010-08-03

I did it... All I did was cut and splice a stereo input jack into the stereo "out" wires for the head unit. They send that sweet sweet signal to my speakers and I blush. :)

BedoF (author)gohenderson2015-11-06

Can you explain more how you did that exactly?

hutchwilco (author)RadBear2008-12-04

yes you can. the cd player module in any single cd player unit communicates (and therefore sends its unamplified audio) to the head units' mainboard and amplifier via a ribbon cable. you just have to hijack your ipd/mp3 player line onto the right points on the ribbon cable, and play a silent cd.

ConradB (author)2015-06-04

This is a great work-around and I can finally listen to my own music in my Nissan Almera SX '06 (which only has FM / CD Player...) There's only 1 annoying issue that I have discovered - when a particularly quiet part of any song is playing, it is drowned out by static / interference / distortion. As soon as the song 'kicks in' or gets louder in any way, all of the above stops and plays perfectly. Any reason why it would do this? If you pause / stop a song there is no static / interference, it only occurs when there is a song playing during a quiet section / intro / etc.

JoseP10 (author)2015-05-08

aldo junior (author)2015-02-12

Hi and nice ideea!

I tried to do this with my Jeep's radio but no sound from other source like iphone or samsung phone. This is my head unit, may be someone will have an ideea.


Twill_40 (author)2014-12-05

question. say this works, but 3-4 months down the road the aux cord gets a short or rips, that means you have to redo this entire process?

laurakasibante (author)2014-06-28

Our car's CD player is broken, so I don't care to keep the CD player an option. (This also means I can't play a silent CD) What would the instructions be to only allow our radio and the external audio device to work? Thanks!

GrimRipper1080 (author)2014-06-27

Thank you for the wonderful instructable! First instructable I've even actually done!

hih313 (author)2012-08-02

Thank you very much
I follow ur instructions. Now I can enjoy listening to music thought AUX

inkyfinky (author)2011-11-22

I hooked everything up perfectly...even used a multimeter to check my connections (and they were fine). With a silent CD playing, I plugged in my ipod and heard that crackle over the speakers (indicating the speakers are hooked up correctly). But then...the ipod stopped playing and just shut off. Has this happened to anyone else? Is the ipod getting a surge of power somehow? Can anyone please explain what is going on? Thank you so much!

Asacer (author)inkyfinky2012-07-03

Use the multimeter to re-check the output power from the jack. However, check both current and voltage. There is a chance there was a surge. I would doubt though, usually a surge at that level would not kiss the entire device. So you might want to check for shorts.

messaround (author)2011-01-24

I looked through this whole thread and didn't see an answer to one of the very first questions posted: Can you somehow use the CD changer interface IF YOU DON'T HAVE A CD CHANGER. I have a radio/cassette deck in my 2004 Sprinter van. I don't like the fake cassette adapter solution or the fm transmitter solution. I might have to settle for one of those if I can't hack an auxilliar input of some kind. So how about it? Can I use my CD changer interface without a CD changer?

Kirstareis (author)messaround2011-03-12

If you have a casette player you are golden!!! Buy a tape with an audio jack at the end of it. Its about 10 dollars at walmart. It has the same audio quality as an aux I personally love it because its cheap. Although try not to shut the wire in your car door it tends to make it die. But thats ok cuz its just 10 bucks LOL. I unfortunately got a new car that doesnt have a tape player :( so now I have to find an alternative.

31mimo (author)Kirstareis2011-12-14

The motor of the K7 player makes to much noise!Solder the 3 wires direct to the reader head of the K7 player!

wmccutchan (author)messaround2011-02-28

You don't need a CD changer to make it work. HOWEVER, your stereo does need the CD changer input. That's the key. If you don't have that output it won't work. His bullet points actually answer this question by the way:

*******************-- Stock car stereo with a CD changer input*************** (says nothing about having an actual CD changer in your car. You probably CAN'T set this up and have the CD changer still working to be completely honest.)
-- Basic Soldering Skills
-- Soldering Iron & Solder
-- Hand held Volt/Multimeter (to find right wires)
-- Small gauge speaker wire (anything around 18-14 gauge will work)
-- 2 panel mount 1/8" stereo phone jacks ($2.99 for 2 at Radio shack)
-- 1/8" stereo plug cable ($5.99 at Radio Shack)
-- Old pair of headphones (really just need the wire & 1/8" plug)

aka_bigred (author)wmccutchan2011-02-28

This instructable isn't about replacing the CD changer, it's sending a pirate AUX signal to the radio. As far as I know, you MUST have a CD changer. At least in my car, it wouldn't work without the CD Changer registering with the head unit.  

Without the CD changer, most head units (ie stereo) I've seen won't even accept (or won't even look for) the signal produced by the changer lines. That's where the silent CD comes in - the head unit thinks the changer is sending the audio signal, when it's really being sent by the MP3 player pirate signal!

@wmccutchan - I originally came up with this because I wanted BOTH the CD changer AND MP3 input, and all the aftermarket interfaces I could find made you swap out the changer for an AUX input but I wanted to add to the stock functionality.

needexercise3 (author)2009-06-25

Wonderful idea, wish I'd been brave enough to try this before! I'll be pulling out my car stereo and having at it.

aka_bigred (author)needexercise32009-06-25

Yep, It's not too hard. If you can solder and are capable enough to remove your car's stereo, you should be able to do it fine. Good luck - you won't regret it after you hear the difference in quality between this and the crappy FM transmitters.!

Lee Wilkerson (author)aka_bigred2010-05-19

The crappy FM transmitters of which you speak can be greatly improved by adding an antenna extension (3-5 feet). I applied this concept to my Belkin and now it only gets a little bit of noise when driving downtown among all the other commercial/industrial transmitters. You can then drape the wire across the top of the dash or tuck it behind trim on the car radio antenna side of the windshield.
Do ya think I should make an 'ible?


we are familiar with your idea of putting an antenna on the transmitter but what we are trying to accomplish here is the elimination of the transmitter altogether. Transmitters aren't very good. They are good if you don't have your own car or you change cars a lot but if you only drive one car then an auxiliary input is the best solution.

eguerra1 (author)jdogtotherescue2011-11-14

Make an auxiliary jack out of the fm transmitter you can hide all the stuff neatly in center console or glove box

aka_bigred (author)eguerra12011-11-14

As jdogtotherescue said, this instructable is about NOT using an FM transmitter as they provide notoriously bad sound quality. This hard-wired strategy gives you CD quality sound.

parekris00 (author)2011-04-27


I have a silent CD, but when I play musicfrom my ipod, I hear only the first 3-4 seconds. Can anyone help me?

thanks in advance

nil8rr (author)parekris002011-10-13

Did you only burn a single track CD? The silent track is only 5 seconds long. If you don't fill the CD with as many silent tracks as will fit, then the CD will only play the silence for 5 seconds and turn off. This might be what's causing your issue.

parekris00 (author)nil8rr2011-10-15

The CD is full with silence tracks. I tried also a silent track of 20 sec. But the problem is still there.
Don't know what to do ..

joeyoung25 (author)2011-09-28

This should be possible. You should only need to connect 3 wires I dont know why you would need 7. If you look at step 2 it shows the diagram of the changer output you should connect the ground pin to the ground on your radioshack jack and left to left and right to right. as far as getting the stereo tricked to thinking its connected to the changer so you can hear audio thats a whole different story and would be completely different between stereo manufacturers. I want to do this same thing to my Chevy Colorado but only with bluetooth. I dont know how possible this is but I dont feel like plugging in a cable to my phone everytime I get in. My phone is mounted in the GPS dock on the windshield so I plan on running a USB port inside of the head liner above the rearview mirror so I should have no wires showing at all but will be able to charge and hear the phone, music, GPS etc. If anyone else reads this and has any ideas of how to wire a bluetooth adapter to my stereo please let me know. It does have an option to have bluetooth handsfree but mine doesnt have it as far as I know.

HoldOnTight (author)2011-08-31

I like how you hid it in the pocket, so the car can be returned to stock if desired! I ran across this because I want to do something like this only my stereo is double-din sized, so I'll try to put it on the edge of the double din frame.

shperka (author)2011-01-09

Thanks for the tutorial! I have a Chrysler Voyager 1995 stereo with a jack to 6 CD Changer, but i do not have the changer. Is it possible to play music via the CD Changer jack without CD Changer? I mean, is there a way to transmit audio signal only with a wiring that will lie the stereo it is connected to cd changer?
Thank you!

flythesky (author)2010-11-24

I don't have a CD changer but do have an Acura CD head unit with plug identical to the one shown. I'm wondering if it might be possible to open up the unit and insert the mp3 player signal into the main CD player output and play the silent CD in the main unit while playing the mp3 player?

xTyD23x (author)2010-06-07

I am doing this in a 2002 Nissan Maxima. How are the wires connected to the aux jack? I bought the one from the link to Radio Shack and don't really understand how to connect the wires properly. I found the terminals on my head unit where I will connect the wires, but from everything I have read elsewhere, I will need to connect 7 wires. I understand where to solder these 7 wires on the board, but what do I do with the other ends???

tmw25 (author)xTyD23x2010-11-01

Hi there.
I'm thinking about doing this to my 2002 maxima as well.

Where did you find the pinout diagram for the cd player?


xTyD23x (author)tmw252010-11-04

Sorry, I wasn't able to get this working right. After I had soldered everything (very poorly) to the head unit, I thought I had it working. I put the disc in the CD player and attempted to play it but it wasn't working. I was pretty depressed and finally gave up and put everything back the way it was. I never found a diagram for the head unit, but I tried to make sense of the labels on the board. I can' t remember exactly what they said but they were labeled and you could figure out what they meant. Let me know if you are successful with this. I usually love messing around with stuff like this but I wasn't able to figure this one out.

anyoldmouse (author)2010-10-25

If I understand this correctly, the idea of making a silent CD is so that the content of a CD and your iPod don't mix. Could you not just pause a normal CD and use the iPod?

aka_bigred (author)anyoldmouse2010-10-25

That may work. I wanted a dedicated disc to remind me I was in "MP3 mode" and not worry about accidentally un-pausing to end up with a mess of music playing all at once.

Whatever works for you.

anku10 (author)2010-07-13

Could this be used as a way to bypass a nonfunctional cd changer? The cd changer in my '03 Camry doesn't work anymore, and I didn't really want to buy a new deck. My entire music library is on various digital devices, so I don't need the CD changer anyway, but I would like to add the auxiliary jack. Can I complete this project with the nonfunctional cd changer?

moiztankiwala (author)2010-06-23

My car stereo is a single audio CD player. Any suggestion on how I can attach the Aux input for my iPod?

maso08 (author)2010-06-14

So this is basically a 5 disc changer with mp3? If you still keep function of the changer, then that is so tight.

aka_bigred (author)maso082010-06-15

Yes, that's exactly what it is.

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