System 10 aux input

Wilrayca

New member
Hi, has anyone done an aux input on a system 10 head unit? Where you tap into the CD player circuit? I have done it on a few other stereos over the years but have no schematic reference for this one. Plus I won’t be able to find another if I mess this one up. :p
 

Wilrayca

New member
If anyone is interested I figured it out and it works very well. Burned a blank CD and picked up $20 Bluetooth off Amazon. Now my 30 year old System 10 can stream music all day long.
There is a small board that the tape deck and CD player both plug into. Google the chip on that board and you can find the pins to solder your aux cable to.
 

simple

Member
Awesome. I used to install a kit that did exactly that for Subaru Legacy. Started a small business around it but it fizzled out as people bought new cars with Bluetooth integrated.
 
Wilrayca, could you provide the rest of us a little more information on exactly what you did? It's too vague for me to do the same.

- what exactly is the Amazon $20 Bluetooth you bought?
- what chip on the board did you google to find the right pins to solder the aux cable to?
- what exactly is the aux cable you used (part number, where purchased, etc.)?
- what is the reference to "burned a blank CD" mean?

I have a bunch of these System 10 head units. I wouldn't mind trying this one on one of them that isn't the best to practice on and see if I can do it. I think this has a lot of potential for these older units.

Is there a way to get SiriusXM through one of these units?
 

Wilrayca

New member
Stupid me at the time I dint take any pictures while I had it apart. But I have another unit on the shelf. I will try to pull it apart this week and get some pics of where I tapped into the board. For the cable its just any 3.5mm jack cable that you would plug any MP3 player or phone in with. The Bluetooth was just an extra option. I bought the Mpow Bluetooth 5.0 receiver from Amazon. 16.99 CAD
The audio cable plugs into that. I will get some pics together and post it up.
 
Thanks for taking the time to educate us on this. Really appreciate it. No rush for me - just want to try it also, given how many of these head units I have (had 4 5th Gen Celicas, just sold one so down to 3, but lots of head units).

Let me know if you know of a way to get a SiruisXM capable receiver hooked into one of these also. Maybe just uses the same 3.5mm jack cable?
 

simple

Member
Yes you would use the auxiliary cable for the Sirius radio input. The burned blank CD is what confuses people. You use that to "play" the source but the actual sound comes from the input like your phone, mp3 player, or sat radio.
 

Wilrayca

New member
I took another stereo apart today and took a few pics.
First after removing the front plate and top plate, take out the CD player unit. 4 screws and two wire connectorsIMG_4519.JPG

The board you need to access is the small one on the RH side. Pull the one screw lock tab off of it. The board pulls up from the connector and will slide out pretty easy. You may have to loosen the square filter unit at the front right corner to get some wiggle room though
IMG_4520.JPG

Once you have access to the board, the connections you are looking for are the two at the arrow. They are connected to pin 6 and pin 25 of the IC chip, labeled as Line out 1 and Line out 2 if you look at the chip data sheet online.
IMG_4528.JPG
 

Wilrayca

New member
Solder your LH and and RH on to each terminal. I then soldered the ground to one of the grounds on the case. there are a few in the same area.
https___i.pinimg.com_originals_57_c6_9a_57c69af622a757d2b814762f8335f518.jpg

Once you have that done, put it all back together. I used hot glue and glued the wire connection down on the board as well. its a delicate solder joint so you don't want any strain on it.
IMG_4529.PNG

I ran the cable out the back of my stereo and into my centre console. Now you can plug any audio device into that cable. I ended up buying a Blutooth receiver off Amazon. Mpow was the brand. $20. It connects to my iPhone every time and has good battery life.

For best sound you should keep your phone at about 80% volume to avoid overdriving the audio.

Basically any input you run through that cable will play through the system whether its on tape, radio or CD. I searched for a blank audio CD file online and burned myself a CDR- with a 30 minute blank track on it. Google "Silent CD" . It pays continuously without every interrupting the aux input.

Now I can use Spotify continuously. Not always for actually listening to music, but to have music in the background to drown out those 30 year rattles! :D
 

Wilrayca

New member
My only disappointment was I really wanted to use the aux when I selected the 'Tape" function. But if you run a blank tape you get the background hiss. I sent some time trying to trick the radio into keeping the tape selection active even without a tape in it, but it was smarter than me and I finally gave up. Maybe a challenge for another day. And since I have one working 30 year old head unit, I am a little hesitant to keep pulling it apart and messing with it!
The quality of the System 10 still blows my mind for something that is 30 years old. Still sounds much better than my other new cars. And I love the look on people faces when they hear it and you tell them you are running Bluetooth in your old car with speakers that you rebuilt yourself, and a completely stock looking centre dash console!
 
This is excellent - I will look to give this a shot.

I'm at work on the other side of the state right now, so I can't compare your pics with what I have. But, could I ask you what Toyota P/N you are working with regarding the head unit? There actually were many different head units used in 5th Gen Celicas that were equipped with the System 10. I'm thinking you have the single large unit with the CD, cassette and radio all in one (86120-33110). But just want to verify first.
 

Wilrayca

New member
Yes. Mine are the double large units with the built in tape and CD. The one in the pics is
86120-2B290, but the one in my car now is a different number too. But same inside. One was from a 91 and the other from a 93
 
Yes, the 86120-2B290 and the 86120-33110 are identical, except for the wiring harness connector (the first with the old 14-pin connection, the last with the newer 15-pin connector). Both are Fujitsu Ten models, so same guts inside. I never saw a factory 1990 with the 86120-2B290 in it, but I put one in my son's ST185 after his CD player went out, and that is working great.

This wouldn't work for the popular Matsushita head units that on the outside look identical though. So I know now you are talking about Fujitsu Ten, and I have several of those. Thanks.
 

underscore

Well-known member
I realized I've got a 86120-33110 sitting in my basement so I might give this a shot. Since you're just tapping into the existing circuit and not interrupting anything I assume it's just "mixing" the aux input with whatever else is selected hence the need for a blank CD?

On a side note don't these head units need a security code entered? How are you dealing with that?
 

Wilrayca

New member
Yes. It just mixes the audio. I know the security code for mine so no big deal. Not sure how to get around that though.
 

underscore

Well-known member
In trying to find the pinout for this head unit to power it up and see if it has a security code set I realized it has a single plug on the back and my car currently has an aftermarket head unit going to 2 plugs. If memory serves that means this is a 90-91 head unit which isn't compatible with the later 2 plug system?
 

underscore

Well-known member
In case anyone needs it I found the pinout. Luckily for me nobody set a security code and at least on the bench it's functional, I'll just have to see if I can actually use it in my car or not.

PIN / FUNCTION
1 AMP Turn On
2 Illumination
3 Accessory
4 Constant 12V
5 Mute
6 Lt Front AMP input (+)
7 Rt Front AMP input (+)
8 Power Antenna
9 N/A
10 Telephone Mute
11 Ground
12 Signal Ground
13 Beep
14 Lt Rear AMP input (+)
15 Rt Rear AMP input (+)

Courtesy of the Metra 70-8112 adapter harness diagram. If you shine a light in the socket you can see the tiny numbers for the pins. I'm half curious what pin 9 is for, even though the adapter doesn't use it the stock radio has a pin there so I assume it does something aftermarket radios don't have.
 
Those head units should only need a security code if one was previously set. If the security system was never activated by setting up a security code number, then the security system is not active.

If the security system is active and you don't have the security code, there is a Toyota TSB to be able to deactivate the current security code number and security system (returning it to original setup before anyone activated the security system). If you need this, let me know, I have a paper copy buried somewhere.
 
underscore":13lqvrlw said:
In trying to find the pinout for this head unit to power it up and see if it has a security code set I realized it has a single plug on the back and my car currently has an aftermarket head unit going to 2 plugs. If memory serves that means this is a 90-91 head unit which isn't compatible with the later 2 plug system?
I believe both the single and the dual wiring harness connection types were used at the same time. The dual type is actually an older type used on head units with internal amplifiers (no external amplifier). The single type is used on head units with an external amplifier (the head unit lacks an internal amplifier). Your 86120-33110 is the 15-pin single wiring harness connector generally used from 1991 and later. At least that is what I have been seeing with these units over the years of having 5th Gen Celicas. I'm sure there are application exceptions out there.
 
simple":26uxdk82 said:
Yes you would use the auxiliary cable for the Sirius radio input. The burned blank CD is what confuses people. You use that to "play" the source but the actual sound comes from the input like your phone, mp3 player, or sat radio.
I know this is a dumb question, but for me, I have to ask - how do you burn a blank CD?

Maybe related, if you can find these terminals on the to "mix" remote input into, can it be done on the cassette side? I still use the CD players a lot, but not the cassette. If something has to be operating to use the remove jack input, I'd be more willing to risk the cassette side than wear out the CD side. But I suppose one would need a blank cassette to make it work. Although I have several cassettes with the auxillary jack in the cassette to do this exact thing. I'm just thinking the sound quality by using a cassette with the jack isn't as good as taking the jack connections directly to the circuit board. Would this be a good assumption?
 
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