DIY Aux Input/Electrical Question/Much Excite!

[Cringe]

There are many products available out there on the market, ranging from the ridiculously cheap to the incredibly expensive. I've been using a cassette adapter since the day I brought the truck home, and it has annoyed me greatly. Insult to injury is the Bluetooth telephone capability, but no media streaming! Today I decided enough was enough, and that I would do something about it.

It is difficult wading through all of the results. More often than not what pops up in a search is in no way related to the GX470. I saw some videos on YouTube and that did help me narrow down what to search for. Finally, after looking at dozens of tutorials on vehicles from Acura to Volvo, I decided to find a manual for the radio.

My truck is an 06 with the ML Nav system. The manual for the radio is CRT2916 and you can find it here:

Download Pioneer GX470 Service Manual

The bit we are interested in is on page 30, but there are some other bits you might find interesting, such as the hidden menu for troubleshooting. I have a lot of my dash torn apart right now since I was about to wire up my 12v USB port. I went ahead and pulled the radio, then started tearing it down so I could get the "motherboard" out. If you look closely you can see where I forgot to remove the cassette adapter before I went to work, but it didn't matter because it came apart regardless!

The top cover just slides off, and the cassette player itself comes out after removing the four screws at each corner. On the bottom is a plastic connector that slides right off, super easy. Beneath that are two more screws that need to be removed, and two tabs which need to be bent straight to release the board from the metal chassis. I did not get a picture of that, but you'll see what I am talking about, they are within these circles that have a slash through them resembling the letter Q. It comes out easily as well.

My pen tip is pointing to the two pins that we are concerned with, the Right Channel and Left Channel of the FM tuner module. If you look on page 30 these are listed as items 5 & 6 respectively. Now, this same page of the manual also brings me to a question that I have not been able to find the answer for. Pin number 10 is listed as Power Supply (5V +/- 0.25v). Would piggybacking something off this cause an issue? I do not have an O-scope so I have no clue what the amp draw/supply of this channel is, I know only what that manual has told me and apparently I am fairly far out on my own here.

Now, you are probably wondering what I have in mind. Originally I was just going to add a 3.5mm female connector so I could plug in an Aux/3.5mm cord to play music. Then I stumbled upon something gorgeous. Behold, the CSR8645 12V Bluetooth receiver board!

https://www.ebay.com/itm/Hifi-12V-CSR8645-APT-X-Bluetooth-4-0-Receiver-Board-for-Auto-Amplifier-Speaker/182917641843?hash=item2a96bdb673:g:vO8AAOSwz~paFSQ9

For the princely sum of $12.19 and some of my time I can have all the features I ever wanted, probably more if I dig into the wiring diagram a bit further. Audio Out L & R will be soldered to Pin 5 & 6. If I don't hear back from anyone else I might get brave and try to power the thing up on Pin 10, otherwise I will have to figure out where to grab 5V elsewhere. Maybe my dash cam power supply. I just have to wait on this thing to show up from China.

If you are still confused, which is a very distinct possibility, my phone will connect to the CSR8645 which will override the FM signal allowing my music to play. The factory phone feature will still work fine. The FM radio will still work fine. If I find the right pins in the wiring diagram I can even make the steering wheel buttons work with the thing. This will all be MUCH cheaper than anything else I have seen on the market...if it all works like it should. If it works, and I see no reason why it shouldn't, I can come up with some better instructions for this "hack".

Hopefully one of you can answer my question about Pin 10, otherwise, let me know what you think!

 

[ciesel]

I applaud your efforts and I hope you find success. I wish I had the skills to do what you're doing. As a backup plan check out Grom Audio. Compare GROM Car Audio Integration Kits

They have a native kit for Audio over USB from phone or flashstick, and over bluetooth. As well as a Native Android add-on unit for the Stock NAV system.

 

[Dharma Dude]

@Cringe, Very cool!

I have been thinking about replacing my CD Changer with a bluetooth adapter like the Grom mentioned by @ciesel
I dumped my CDs years ago, so the CD changer is taking up valuable space. I'm about to try the Yatour unit.
They're available on Ebay and Amazon for around $75.00 + $15 for the Y-cable for GX's with Nav.

Not as cheap as @Cringe but for somebody with my skills, result in a cleaner solution.

 

[Cringe]

For those who are hesitant to gut their head unit and frankenstein in the module it would be possible to wire it into the CD changer harness, but you would have to play a blank CD to get any audio (tricks the radio into thinking its the CD providing the input). I was doing some more reading last night before bed, but did not find a definitive answer on the steering wheel controls. Some say it is handled by CANBUS, some said it was changing of Ohms when the switch is pressed and not something so simple as on/off. If the information was easier to find then this would be an easier project to tackle! The actual doing part is not difficult at all, its the rest which is a true pain in the butt. I imagine the service department would give me a blank stare if I went there to ask them questions like this, and I don't have any electrical engineers handy!

 

[Cringe]

Double-tap.

 

[Augie]

The PO of my truck wire an IPOD wire to the CD changer input. I do not need to run blank CD. I just have to select CD and could play music thru it. I don't own any apple product so I just bought an adapter from apple to 3.5mm jack and wire it to my Bluetooth adapter .

 

[Dharma Dude]

For those who are hesitant to gut their head unit and frankenstein in the module it would be possible to wire it into the CD changer harness, but you would have to play a blank CD to get any audio (tricks the radio into thinking its the CD providing the input). I was doing some more reading last night before bed, but did not find a definitive answer on the steering wheel controls. Some say it is handled by CANBUS, some said it was changing of Ohms when the switch is pressed and not something so simple as on/off. If the information was easier to find then this would be an easier project to tackle! The actual doing part is not difficult at all, its the rest which is a true pain in the butt. I imagine the service department would give me a blank stare if I went there to ask them questions like this, and I don't have any electrical engineers handy!

This problem has been solved by Yatour, VAIS, and Grom (Actually they probably just use the same chip set made by one company) They in fact, emulate the CD changer, and the figured out the funky way that Lexus/Toyota has wired up the NAV/CD changer/Radio. The latter is the hard part to get the emulation working.

 

[Eporter]

SO...... @Cringe what happened?!

 

[runningdrew]

The PO of my truck wire an IPOD wire to the CD changer input. I do not need to run blank CD. I just have to select CD and could play music thru it. I don't own any apple product so I just bought an adapter from apple to 3.5mm jack and wire it to my Bluetooth adapter .

I need more info on this. I just want a hard wired AUX input cable for now while my mobile phone still has a 3.5 mm input. I'm still so mad phone makers think that is old tech.

 

[Cringe]

SO...... @Cringe what happened?!

I soldered a 3.5mm port onto the cassette player while I was waiting on the board to show up on the slow boat from China. It worked fine, and to my knowledge is still working fine. My pop-up camper lift mechanism broke, and since we had really outgrown it we decided to finally get a bigger travel trailer. That led to me selling the GX and going back to a truck, so I haven't been on mud much lately.

 

[runningdrew]

I soldered a 3.5mm port onto the cassette player while I was waiting on the board to show up on the slow boat from China. It worked fine, and to my knowledge is still working fine. My pop-up camper lift mechanism broke, and since we had really outgrown it we decided to finally get a bigger travel trailer. That led to me selling the GX and going back to a truck, so I haven't been on mud much lately.

Did you solder a aux cord onto a cassette adapter, or open up the radio/dash and solder the 3.5mm cable wires to the cassette connections for a permanent connection? Does a dummy tape have to be in the cassette player for it to be recognized. I'm intrigued and would love to know if there was an online guide you followed? Thanks

 

[Cringe]

I opened up the radio and soldered directly to the cassette player itself. If it failed then there was no worry of not having any tunes! I did keep a dummy tape in there to activate it, ejecting the tape obviously cut the feed, simple stuff. My grand plan was to go from the Bluetooth adapter to the FM tuner module, eliminating the need for cords entirely. I got my board from China but did not know I needed a 10k ohm resistor for the switched power supply. I spoke with a person who told me about the resistor for the on/off of the board, but by that point I had already let the magic white smoke out.

The documentation from the factory was all in Mandarin, and the English translations I found were not the greatest, which is why I missed the bit about adding the resistor. If you are just using a 3.5mm cord then there is no need for any of that though. Just strip the wires and solder them to the + & - terminals then you are in business, if you have that dummy tape and are going the cassette player route. I some YouTube videos and tried reading on some different forums, but there was no online guide for this. That was what I had planned to do once I had all the bugs worked out, write up a decent guide, then people wouldn't be stuck buying $100+ adapters if they didn't mind doing the work themselves.

 

[alzrnb]

Hey Cringe, I'm sure you want to move on since you no longer own your GX, but do you happen to have any pictures from your completed tape deck aux port? I'm hoping to attempt this soon as we just got our Prado and the tape adapter is just not cutting it!

 

[runningdrew]

I 2nd that vote/request.

 

[Cringe]

No worries! This all sounds a lot more complicated than it really is. I tried looking, and the only photos I have left are those that are posted at the beginning of this thread. However, I did a quick search and found another mud member who did the same thing with his LX470. This photo belongs to AnthraxVX, and it shows where to solder your input wires to the tape deck.

I used this 3.5mm jack since a 1/4" drill bit made the perfect size hole and it was easy to conceal down in the recess area in front of the shifter:
Panel Jack

And the following video shows how to do it as well:




I figure this ought to get the ball rolling for you. I'd suggest some trim removal tools to help get the dash apart, makes life easier and you won't break any of those tabs off. While you're in there you could add something like this to fit in one of those switch blanks so you can plug in a charger as well. Oh, and a grommet to pass the wire through the radio chassis so it doesn't chafe and short. That should about cover it, but if you have any more questions feel free to ask!

 

[alzrnb]

Awesome thanks my man! So the ribbon cable which needs to be cut/de-soldered does make this a destructive process in terms of the tape deck then? Or is it possible to make it all work without breaking that connection as long as a blank/dummy tape is being used in the deck?

 

[Cringe]

Awesome thanks my man! So the ribbon cable which needs to be cut/de-soldered does make this a destructive process in terms of the tape deck then? Or is it possible to make it all work without breaking that connection as long as a blank/dummy tape is being used in the deck?

If I am remembering correctly you can just unplug that ribbon cable, similar method to the one you'd use replacing a laptop keyboard or any other ribbon cable. Should pop out of a "molex" connector, and be able to be plugged in again. I also believe you can just leave the ribbon cable intact and use a dummy tape. Worst case scenario: solder your wires and leave the ribbon cable alone, test it with the dummy tape, if it doesn't work then pop the radio back out and disconnect the ribbon cable. I really want to say I left that cable connected, because I remember finding an old cassette in the bottom of a foot locker and played it in the Lexus to see what was on it.

 

[Bralow]

@runningdrew @alzrnb Did either of you ever end up doing this?

How did it go? Pics? Advice?

 

[isthatalexus]

No worries! This all sounds a lot more complicated than it really is. I tried looking, and the only photos I have left are those that are posted at the beginning of this thread. However, I did a quick search and found another mud member who did the same thing with his LX470. This photo belongs to AnthraxVX, and it shows where to solder your input wires to the tape deck.

I used this 3.5mm jack since a 1/4" drill bit made the perfect size hole and it was easy to conceal down in the recess area in front of the shifter:
Panel Jack

And the following video shows how to do it as well:




I figure this ought to get the ball rolling for you. I'd suggest some trim removal tools to help get the dash apart, makes life easier and you won't break any of those tabs off. While you're in there you could add something like this to fit in one of those switch blanks so you can plug in a charger as well. Oh, and a grommet to pass the wire through the radio chassis so it doesn't chafe and short. That should about cover it, but if you have any more questions feel free to ask!

A big thank-you to you, @Cringe! I decided to tackle this mod while everything was apart for the Expedition Essentials GXPAM install. The correct PCB was easy enough to identify and liberate. I've soldered twice in my life, and I was able to make this work successfully. Here's what I will fix when I open it up again, and what I recommend others do when they do the tape-to-aux mod: install a ground loop noise isolator like this. Reason: when the 1/8" jack is piping music to your system and you're charging the phone, there is a tremendous amount of interference. I think without the GLNI you've effectively rigged up an unintentional AM radio.