speedkar9

I made a short video on how to hack an auxiliary input to your car’s stereo:


Adding a 3.5mm jack is the cheapest way to get a clear audio signal from your phone to your car’s stereo, without having to worry about distortion or interference with a cassette adapter or FM transmitter, aftermarket radio wiring, or expensive MP3 adapters.
The first thing is to remove the radio from the dash.

The console lid, radio side trims, driver’s lower footwell cover (under the steering wheel) glovebox and clock need to be removed to get at the radio screws:

The side panel screw on either side is hidden behind the glove box and driver’s footwell panel:

One screw behind the clock:

Two screws below the radio:

Then disconnect the radio. If you have navigation, its heavy:

Begin to remove all the screws to take apart the headunit:

Remove the GPS or storage cubby and separate the radio face:

Remove all the screws from the stereo casing:

The 6 CD changer:

The cassette deck:

This radio has three main inputs, the radio, the cassette and CD:

Flip the board over and you can see the connector solder points that we are going to wire a 3.5mm headphone plug to. On this radio, it’s a direct connection since they are all analog inputs:

For the cassette deck, the left, right and ground are clearly marked. You’ll need a blank cassette tape to trick the stereo into thinking there’s a cassette in the drive and read from that source. The sound will still be clearer than using a regular cassette adapter because it doesn’t have to go through mechanical conversion to the magnetic tape stripe. Furthermore, the head from the cassette player can be disconnected to rid of the hiss noise that the blank tape may create:

For connecting through the radio lines, the right, left and ground channels are clearly marked under the tuner. Simply solder to a 3.5mm jack, and the audio from your device will simply override the audio from the radio tuner:

For connecting to the CD changer, the Left, right and ground channels are clearly marked. In fact, the ground is common for all three inputs. The CD drive will require a CD with a silent CD track burnt on it to play in order to trick the headunit into reading from the CD drive. It will also work with a CD that has music on it, though it could mess up the audio system when you disconnect your phone, so a silent CD is recommended.

I soldered wires to all three inputs and routed them out of the case to test inside the car:

Here is the completed “harness”:

The heart of this aux hack is a 3.5mm cable which you can get from the dollar store for $1. You can also get a female jack and bolt it to an interior trim panel, such as the radio face or center console. The 3.5mm plug has left, right and ground wires that connect to the respective wires soldered earlier.

Plug everything into the dash and try out each input.
The CD player method worked the best, followed by the radio. The cassette player method didn’t work directly due to the jack detection on my phone not detecting headphones were plugged in, though I did hear a static pop when I plugged it in so I’m sure it’ll work with other MP3 players.

Enjoy!

riredale

Sorry, man, but come on. This is a joke, right? Is it already April 1?

How about this solution? Get a little adapter that takes in your audio and puts it on an unused FM band. I used a cheap "Colby" adapter for years that plugged into a 12 socket and delivered surprisingly-good audio.

No soldering necessary.

b2884987

I use a cassette adapter or a Grom unit on my car. Works like a charm.

pman6

a cassette aux adapter doesn't sound like crap?

speedkar9

The cassette adapters are subject to hissing sound from the moving tape and a lot of static. For a clean connection, hacking the CD lines is the best.

Sherl

If you open even my 98 Pioneer board, you can't read it. Its just plain numbers everywhere.

evident

This also looks like an Infiniti g35/ 350z... they have aux harnesses that are easily adaptable for many cars too.

Johnhav430

My issue with our "old" cars is the LS430. I have these limited edition CDs, so instead of opening them, I want to play them from mp3 that were made from streaming. Because I can record them from streaming even though nobody allows downloading. But mp3 to CD is really inconvenient, whereas with aux they could be played from source....too bad for me lol (the other old cars have aux and USB, USB being convenient). Remember mp3 is lossy so even though say 250 mb worth of music, it's 2+ hours so each cd can only hold 80 min. Of course the simple solution is to open the cds so the LS430 can play them. CDs likely sound the best anyway...letting the ML do the conversion to analog.

pman6

hey speedkar9

can you hack your gs350?

I have the same car, and want an aux line without using some ebay aux box.

speedkar9

I've got that request before, but to be honest I'm kinda scared to open up my Lexus headunit because they are so expensive to get if I screw up. I have a GTA Car Kit adapter installed for aux in mine. My brother opened his G37 radio last week to attempt an aux hack similar to my G35 and almost messed it up...the car almost didn't want to start. Luckily it was just a forgotten ribbon cable.

Now I did hack a GS300 radio going through the cassette deck's lines that might be similar to the GS350 with cassette:

TerrySmith

I had to replace the heater fan inside the console on my '74 Volvo 144 GL back then and the instructions for doing that were almost the same as the instructions in post #1 except I also had to remove the driver's seat.