I'm doing a project on my Miata that might be of interest to CB7tuners.

[deevergote]

In the next couple weeks, I'm going to be adding bluetooth connectivity to my factory head unit (from 1990). Stealthy. Completely hidden, other than a switch (which could also be hidden.)
I'll be following this, with a few minor alterations.

Now, I haven't unearthed one of my factory CB7 head units to see if anything here applies to it... but I figured I'd share in case someone can make use of it!
I'm putting this in OT rather than OA or Audio because it's not really a how-to, and it's not really a thread about my car.
If I can figure out how to translate this to the CB7, or if anyone else can, I'll make (or encourage) a DIY thread.

[illinois_erik]

thats awesome! good luck. I looked into something sort of similar for an older badass panasonic head i had, the only thing that killed it was, the din connector expected some sort of digital pulse from the optional cd magazine, and the converter cable was like 40 bucks..
I imagine the oem radios wernt as sophisticated back then. the two oem's radio's probably share a lot of IC's (Japan) when getting into the meat of things, so whatever adventure you go on, can probably be distilled down for Honda use... and your project made me think of this..lmao

[deevergote]

I actually thought about doing that!
I'm going to route a charging cable into the little cubby in the armrest on my car. Got the idea from my Fit

I'll hopefully be able to dig out a radio from one of my CB7s later today. If we have a connector on the back similar to the one on the Mazda radio, I should be able to locate a pinout for it. Once that's done, this should be able to be adapted to a CB7 quite easily.
I absolutely LOVE the idea of having a decent MP3/streaming solution without the need for an aftermarket head unit. Totally removes the temptation for thieves. On the Miata, it's almost necessary... because soft tops are easily sliced (and I'd rather not replace a $300 soft top AND a $200 head unit!) CB7s are still common targets for theft as well, so this could come in useful. Nobody uses CDs anymore anyway!

[lucifer1]

Here is full pinout of the Mazda radio from an old Sony oem integration manual



You can do the same thing with a 90-91 accord radio. The 92-93 accords are cd changer inputs and not a pre amp loop

[deevergote]

Ah, there we go! I should've known you'd be the one to know what's up with that! You really are the DIY king around here!

Cool, so the 90-91 should be able to do a similar mod. I like the idea of keeping the factory appearance, while adding updated functionality.

[lucifer1]

Here is for the 90-91 accord


Add a wire to the 'cd remote' terminal on the main connector. Apply 12V to switch audio over and 'CD' will be displayed on the screen. Remove 12v and audio will switch back.

[deevergote]

Ok, so I got the basic wiring started today. I picked up a pre-wired 13 pin plug, a DPDT switch with screw connectors, and a RCA to headphone cable.

I cut off the RCA ends, twisted and taped the ground wires together (bad idea?) and taped them up. Stripped the sheathed wires inside the cable and attached them to the switch. I attached the 4 necessary wires for audio in and audio out from the 13 pin cable, and taped back the rest (isolating the two power wires.) I didn't tie anything together with ground wire as the diagram says to do.

The results were... not good. I got parts of songs... like vocals or guitar only. Low volume, and the radio bled through when I turned it up. Something is definitely screwy with my wiring! I'll have to try it again with a ground wire... or just tear it all apart and do it over again
It kinda worked, so I'm on the right track at least!


I didn't incorporate the bluetooth device yet. I'm going to install a hidden secondary cigar outlet with a USB adapter, and just power it that way. No messing with resistors and whatnot if I do it that way!

[lucifer1]

You will need to tie the all signal grounds together.

Pre amp input connected to the switch's common pole?

Are you putting power to the pin12 remote input?

[deevergote]

I have all wires but the ones going to pins 1, 2, 3, and 4 tied back. Wires for pins 7 and 8 appear to be powered, so I taped each of them up separately before adding them to the bundle of unused wires. For the moment, I'm not bothering with the bluetooth, so I don't need to tap into any power lines. I'm just going for an auxiliary input cable at this point. Once that's working properly, I'll power the bluetooth device from the cigar lighter circuit, and just plug the auxiliary input cable into it.

The wire on the 13 pin connector has a ground incorporated into it. I tied that back with the rest of the wires, which may have been my mistake. Do you think it would be enough to simply run that wire around the 4 wires that I used, and then connect it to the grounding screw located on the back of the Miata's head unit?

[lucifer1]

The pin5 signal ground needs to be connected to RCAs signal ground

[lucifer1]

I would also put power on the remote input wire when you switch over. Try connecting with the pin 9 5v output first. If that does not turn off the tuner then try 12v.