installing aux input on stock radio w/o purchasing an expensive adapter

[jdoggsc]

Has anyone here tried doing this on a 3rd-gen Protege? I spent a bit of time yesterday scouring the interwebs for how-to's. I came across several like this (for a Mazda 6) which said to jumper pins 1 and 13 to get a button ("Media" button) to function so you can switch the input to come from that port.

I also found different wiring diagrams like this (again, for a Mazda 6) and this (for a '97 Protege) that are not only completely different from each other, but different from mine.

The connector looks the same on all of these radios. The protege head unit has no "Media" button that it looks like you can enable, but I'm hoping to get results more like the 97 protege at the link above.

Ultimately, I am trying to avoid doing this (also seen here on a Mazda RX-8) because it's more invasive than I'd prefer. I would do it, though, if there were no pin-out option that would work.

The goal of this forum is to get a functioning aux input WITHOUT purchasing a Grom, Auxmod, GTA Car Kit, or other similar expensive adapter. I already know these adapters exist.

For reference, for curious tinkerers who would like to compare their set-up to mine, the part number of my unit is BL8D-66-AS0

Has anyone gone this route? Any leads would be greatly appreciated.


Responses recommending any of the suggestions below will not be considered useful, and should not be posted:
-buying aftermarket head unit with aux input (using stock head unit is the goal)
-buying expensive adapter (Grom, Auxmod, GTA Car Kit, or other similar), which defeats the purpose of this thread

 

[mp5la]

Not sure if this will help, but this is what we use on the Subaru factory radios. http://www.jazzyengineering.com/index.php?cPath=21&osCsid=rrt1hktpa59nsa7p6og6hmlbh4 I don't know if you could adapt one of those to work, or if they'd be interested in making one for you.

 

[sleepwalker]

Edit: saw the disclaimer at the end of the OP. Never mind.

 

[jdoggsc]

I checked resistance across pins 1 and 13 (which apparently enables the "media" button on the Mazda6) and there was infinite resistance--so that putting a jumper there would be useless. I saw another wiring diagram showing the same thing, but instead of putting it on the 7th pin over, they put it on the 6th pin over. I checked the resistance across those, and got sometime, so I thought I'd give it a shot. I still got nothing.

Since we don't have a "Media" button, I was hoping that somehow this could enable the "Tape/MD" button in the middle of my head unit. There is, however an open port on the bottom on the head unit where a tape player would go (same connection as the head unit uses to connect to the 6-cd-changer above it).

 

[mp5la]

That link I sent you does something similar. It uses a patch cable to piggyback into the CD player. The cable runs from the cd player to the aux in and then to the head. A silent cd is then played to fool the player into thinking that its running a cd.

 

[jdoggsc]

Thanks for the reply. I was initially hoping for something like that because it looked simple. to just tap into the signal and then use a silent CD to trick the HU into pulling signal from that source. The problem is that there are no wires coming from the CD changer into the main unit, so there are no signals to intercept along the way (that I know of). I suppose if I knew the pin-out of the interface cable, I could do that?
The unit looks like this:

the top part is the cd changer. there is an interface between them that's almost impossible to get to. someone made this device, which connects to the bottom port and costs money.

but there's a port just like that that's sandwiched between the main unit and the cd changer that you can't really intercept.

 

[cyrus1979]

I have the same, well at least similar, stereo in my 2003 protege, 3rd gen. The stereo is modular, meaning if you could find one, you could add a tape deck. But forget that junk. But would it be possible to pop out the CD player and directly piggy back on its connector to the head unit? We could let the wires out the back through the wee circuit board window or perhaps drill a hole. Either way that would be a very neat way to do this. But I'm retarded and need a how to.

 

[jdoggsc]

I have the same, well at least similar, stereo in my 2003 protege, 3rd gen. The stereo is modular, meaning if you could find one, you could add a tape deck. But forget that junk. But would it be possible to pop out the CD player and directly piggy back on its connector to the head unit? We could let the wires out the back through the wee circuit board window or perhaps drill a hole. Either way that would be a very neat way to do this. But I'm retarded and need a how to.

This is exactly the kind of know-how that I was probing for. It doesn't look like there's much for the Protege.

Popping off the cd changer and piggybacking onto its connector is what I'm going for too. There's really no point of disconnecting the cd changer when the tape/minidisc port on the bottom has an identical port, but is not being used at all. It'd even be easier to push the "Tape/MD" button and get aux than to have to worry about having to play a silent CD on repeat. Just like you, though, I don't have the know-how!

I've tried probing the connectors on the bottom where the tape/minidisc player goes. I can find a ground, a +12V constant, and a +12V that's on when the key is in. I think I also found a +5V pin (relative to the pin that I'm considering ground ) but as far as recognizing which pins represent left,right,and speaker ground, I don't know how to recognize them from voltage/resistance values.

Is there any way to recognize a Lspeaker,Rspeaker,and Speaker ground wires just by their electrical properties? Or is the only way to disassemble the head unit and hope that (1) you don't accidentally destroy your head unit, and (2) the words/letters L,R,GND are written on the circuitboard somewhere?

 

[cyrus1979]

I found this today, http://mazda-speed.com/faq/audio/#CDTape
Maybe you can do somthin with it. The tape thing is certainly desirable. I don't have a media button or whatever. However...
Would it be possible to do something that would care for BOTH charging AND playing music through?? I don't know...maybe like go USB instead of aux?? I have dismantled a dual charger..:

Here is the board..:

Is it possible to just tie the power in from the exixting lifhter and then tie usb into midi/tape via data L/R to speaker L/R?
And maby the accessory pin? I mayb breaking circuitry laws but it would be greatness!!

 

[jdoggsc]

that link is a really good reference! The J-02 connector matches what I found by probing it with my multimeter. Even if you were to connect stuff to it, I don't know how to make the head unit use the sound input from it, so the CD/Tape ports seemed like a more sure bet. TNS? ILL? NC? I have no idea what it means, or how to use that stuff. I want to try connecting the R,L, and S GND connections, and see if that's all it takes to output audio as desired. If so, then that is exactly what I've been looking for!

As for charging, that's the easy part. You can use the BUS GND and ACC (+12V) connections on either the J-02 connector or the Tape connector. the 4 pins on a USB cable are GND,-Sig,+Sig,+5V so you just need to use a voltage divider to bring the 12V ACC source down to 5V, and then just solder the USB to your +5V signal you made and you've got a charger!

I suppose you could also splice into the cigarette lighter, but that seems unnecessarily destructive. This would do the same thing.

 

[cyrus1979]

I certainly don't need extra lighters. But I believe this voltage divider you speak of may already be built into the USB circuit board as it is powered by the 12v power outlet. Would that be accurate you think? If so I could just attach the acc and bus to this points and then it's just see if the data will go through the L and R pins?

 

[jdoggsc]

I certainly don't need extra lighters. But I believe this voltage divider you speak of may already be built into the USB circuit board as it is powered by the 12v power outlet. Would that be accurate you think? If so I could just attach the acc and bus to this points and then it's just see if the data will go through the L and R pins?

Yes, you could attach your device directly to the +12V Acc and BUS GND pins. I don't know what you mean by having data go through the L and R pins. If you plug your device into the USB port, it's not just going to output the L and R signals over the USB like you want. you'll have to take a audio jack from your device and connect that wire to the Tape connector like the diagram shows.

Maybe I misunderstood you...I dunno. It might be a few days until can try connecting up something to that Tape/MD connector to see if the L,R, and S GND contacts will work. If you get around to it before then, please let me know how it works out!

 

[cyrus1979]

Sorry. By data I meant music. Ie: plug my iphone into the USB jack and play music. My real goal is to play and charge via one jack, usb.
Is the music supposed to transmit thorough the -sig and +sig? And your saying that will not work if I connect those to the L and R? I know cars have usb built in nowadays, is it not possible to copy that? If not, is there a way to jump up and down and make it work?

 

[jdoggsc]

I found this today, http://mazda-speed.com/faq/audio/#CDTape
Maybe you can do somthin with it. The tape thing is certainly desirable. I don't have a media button or whatever. However...

I finally got around to pulling back out of my car and tinkering with it. I used the pinout in the link above as a reference, and tried grounding several pins to the ground, and then pressing the MD/Tape button to see if grounding one of those pins would make the receiver think something was attached there. No luck. I can't get my receiver to switch to the MD/Tape mode. Once there, I believe I can find which pins are for the audio inputs.

Any suggestions?

 

[lowlevel]

Also tried this, and different pins on my 2002 protege5 deck... didn't get anywhere with it... but check this out:

http://nikosapi.org/w/index.php/MazdaSpoof_-_A_Tape_Deck_Emulator

This looks like the only one that would work for mine... It pretends to be the tape unit.
I just went with an aftermarket unit since my radio tuner wasn't working either.

 

[benzing]

i would like to have my stock head unit to use a usb or aux cable to it while making it look stock without destroying my stereo. i have a 2003 mazda protege es with the premium sound and my tape button is useless right now. wondering if its possible to make that an "aux" button