Introduction: Add an Aux in Jack for Clarion Stereo Head Unit (In Subarus)

Add an auxilliary input for your Ipod or MP3 player, if you have a Subaru with a factory fitted Clarion CD player.

This works for Clarion drx6275gv as fitted to my '99 Subaru Liberty (aka Legacy if you are outside Australia), but also works for various other makes and models that use Clarion with C-Bus connection (13 pin din plug at the back for use with CD changer). I found a web site that seemed to use the same unit for a 1997 VW Jetta.

Now my car does not have the optional CD changer, so I was able to hijack the CD Changer input to use as an input for my Ipod.

For this project you will need:

A Clarion Head unit (the bit in the dash board) compatible with CD Changer
A toggle switch (or other switch capable of on & off functions)
A stereo capable socket or jack compatible with your brand of MP3 player (ie 3 conductors)
No1 & No2 Phillips head screw driver (a stubby No2 is also required)
Fine tipped soldering iron
Some electromechanical aptitude would help.

Remember: It is Your car & Your responsibility, so take care & enjoy yourself!
Note also that cars differ over time & space, so if you find variations in your car, maybe you could add some comments to this highlighting the differences.

Step 1: Removing the Stereo Head Unit

In case you have the same car as me, here is how to remove the stereo: (as mentioned, gen 3 Subaru Liberty - aka Legacy)

1) lift the plastic moulding surrounding the gear selector knob (Manual only -Auto drivers will have to figure that out themselves - sorry!). It is held by 4 spring clips spaced at each of the corners adjacent to the cloth surrounding the selector lever. Be careful, there are 2 clips holding the moulding just below the seam to the stereo/climate control bezel. I broke both of them on my car (not that it made any difference). Unscrew the gear selector knob

2) unscrew the two screws holding the rubber lined tray just below the ashtray. Remove the tray.

3) remove the ashtray (push the top flap down to slide out past the detents).

4) In the metal ashtray mount, there are 2 hidden screws. You need to remove these. They are screwed through the metal up into the plastic bezel above. You need a short No 2 phillips head screwdriver. Allow the metal plate to drop down (it is still held at the back, but you don't need to remove it).

5) The stereo/climate control Bezel (mine is that fake wood type) will now snap out. Careful not to be too rough & break it, but it should come out. The cigarette lighter has 2 looms attached to this bezel. You will have to disconnect them to remove it.

6) You have now exposed the mounting brackets for the stereo, climate control & (in my car's case) 2 trinket trays. There are 6 screws holding these brackets to the car's chassis. 2 each side & 2 below. Remove these screws, taking care not to drop them as you might never retrieve them! (Use a magnetic tip screwdriver if you have one)

Warning! the airbag control unit is just below here, careful not to short it out, or you might well set one off. Consider disconnecting the battery, removing fuse or other precaution.

7) Manoeuver the assembly out of the recess in the dash. Disconnect the loom at the back of the stereo as well as the 2 aerial plugs (yes I found 2 plugs. Don't ask me why). unscrew the 4 screws (2 each side) of the stereo head unit. You can now slide it out of the assembly.

Step 2: Identifying the Inputs

Now that you have the stereo head unit out, there are two ways to connect to it. First one is to try to find a 13 pin DIN plug that connects to the back of the unit, where the CD changer normally connects.

The second is to remove the cover of the head unit and solder wires directly onto the PCB where the DIN socket is. I chose this as the easiest way of connecting to the stereo (the plugs can be hard to get).

In the image below, you can see the pin pattern for the plug in the back of the head unit. If you decide to find the plug, then you will need to wire the corresponding pins on the plug.

Firstly you will need to make a cable to go between the DIN plug and the Jack for your AUX input.

secondly you will need to include a switch to tell the head unit to accept the signal from the AUX jack.

pin 6 is the signal ground
Pin 7 is the Left hand channel signal
Pin 8 is the Right hand channel signal

Pin 5 & Pin 9 are to be switched together to put the head unit into accessory mode

If, like me, you can't find a 13 pin plug, (or in reality haven't got the patience to wait for one to arrive), then you can remove the bottom cover of the head unit & solder directly onto the corresponding pins on the PCB.

(by the way, I'm not sure of the origin of the image below. I found it with no claims of ownership, but if by any chance you are aware of it infringing any copyright, please let me know & I will remove it.)

Step 3: Identifying the Solder Pins

Turn the unit upside down & remove the two screws holding the bottom cover on.

You will see the solder terminals corresponding to the pins referred to on the previous page.

The PCB has labels which make identifying them easier.
The signal pins are clearly labeled as left and right, as is the signal ground (don't use the regular ground)

The switch pins are not so obvious, one is CD-IN, and the other is diagonally adjacent to it.
In the photo, you will see a red wire soldered to the right signal pin, a white wire soldered to the left channel signal, and a grey wire soldered to the signal ground.

The purple wire is soldered to the CD-IN pin and the blue is soldered to the diagonally adjacent pin (next to the grey ground wire). Take note, the blue wire is soldered to the pin located to the right of the end of the wire, not to to pin labelled SI/SO

(Those of you familiar with electronics will notice the exposed copper track....That was the result of shorting the wrong pins I was trying to identify the correct pins :-)

Step 4: Finishing the Stereo Modifications

I cut away a small corner of the bottom cover to allow the wires to exit the head unit without being crushed.

I also squirted some silicone onto the joints to avoid shorting out problems later. I suggest you use the silicone that is acetic acid free, otherwise you will be digging rust out of your dash for the next 6 months, and your car will smell like a fish & chip shop.

Once this is done you can replace the bottom cover onto the head unit.

Step 5: Adding a Jack and a Switch

On the other end of the wires, solder a stereo jack of a size that will allow you to connect an Ipod or other MP3 player using a jumper lead. I used a 3.5mm TRS jack.

The signal wires, to be connected to your MP3 player, (red, white & grey) need to be soldered in the correct sequence to avoid damage to your player. The grey (ground) wire should be attached to the terminal which is closest to the outside of the jack. The tip and the intermediate ring being for signals (left & right). If in doubt, ask at your local electronics store. It does not matter if you get the left & right reversed, the music will just come out different speakers.

The purple & blue wires (in my photo) are soldered to a switch. I used a toggle switch, but you can use whatever fits with your car's style....

I placed the switch and the socket in the back of the trinket compartment below the stereo. Drill holes of the appropriate size for the switch and socket you have selected & screw the two components into the resulting holes.

Step 6: Finished - Reinstall in Your Car

Now you can install the stereo head unit & trinket compartment back into the car, reversing the steps in step 1. Don't forget to plug all the plugs back in (2 aerial, 1 loom to head unit & the looms to the ciggie lighter)

I suggest you test the unit before you do this to make sure you have wired everything up & that it works as expected before you put the car back together.

Note that when you switch the switch, the stereo shows the letters "ACCS" (see photo below). This means it will accept any input from the jack you have installed. If you want to listen to the radio or a CD, switch the switch to off, and the head unit will return to normal.

Total cost for me was $0 as I had a spare switch & jack, but you should get them for less than $10 for the lot.