Adding Bluetooth to Older Car Radio

[XJohnDoe001x]

Friends, help me understand what I have to do. I have an older car radio with cassette player, I also have a Bluetooth adapter that plugs in a Apple sound dock to allows Android devices to connect via Bluetooth.

I am thinking that I can find a way to adapt it to replace the cassette players tape head.

Yeah! Yeah!, I Know buy a new radio or use one of the many other methods. That'll take the fun out of the adventure of the challenge

A link to the device that I have is:
https://coolstreamrocks.com/coolstream-duo-bluetooth-music-receiver/

 

[davenn]

A link to the device that I have is:
https://coolstreamrocks.com/coolstream-duo-bluetooth-music-receiver/

well that's a start
now the important bit … you gave absolutely no info about your car radio ???

your first mission would be to get a service manual or at least minimum a schematic of the radio

 

[dave9]

If you can't get a manual or schematic then you should consider whether it's mechanically switched input or logic switching a mux (multiplexor) chip.

If mechnically switched you might just need to connect the analog from the BT to the switch and sever the cassette feed, and put the ground from the BT analog somewhere that the low level signal doesn't get swamped by ground loop current. The cassette module output, ground point should suffice.

If muxed you would do similar, sever the cassette input and wire the BT to that respective input pin. You can trace this with a multimeter (or maybe y o u can't )

Keep in mind that with a radio that old, you might soon enough have display problems, switch problems, rotted capacitors, etc. It's a bit old in its service life to redeploy for this purpose unless you refurbish the whole thing. Otherwise you can pick up used radios at a junkyard for cheap and play around with one of those that's quite a bit newer.

Something I would keep in mind that can take away from the fun and adventure is that once you have pulled the car stereo, you are left without tunes until it is completed unless you reassemble and reinstall it till needed parts arrive then uninstall and disassemble it yet again to complete the project. Is it a classic car and you *need* the original radio to preserve the factory look? If not, I would not try to.

 

[XJohnDoe001x]

well that's a start
now the important bit … you gave absolutely no info about your car radio ???

your first mission would be to get a service manual or at least minimum a schematic of the radio

I am sorry, I made an assumption that cassette pick up head specifications were standard, that is that the current output is about the same across the industry and that the output of the Bluetooth device would be more pertinent.

My question is preliminary to delving into the specs and meat, anyway I will have to pull the dashboard off and pull it to get the exact make and model information but it is a JBL 6 disk changer with a cassette player.

 

[XJohnDoe001x]

Friends, help me understand what I have to do. I have an older car radio with cassette player, I also have a Bluetooth adapter that plugs in a Apple sound dock to allows Android devices to connect via Bluetooth.
UPDATE
I am thinking that I can find a way to adapt it to replace the cassette players tape head. UPDATE! I meant to say replace the pickup head with the Bluetooth device

 

[XJohnDoe001x]

Thank you for the awesome reply, exactly what I wanted and.. . . . WAIT! WHAT! NO. SOUNDS NNOOOOOOOOOO!

No really, I swore off of broadcast long ago, DJs talk too much and have horrible sense of humor. Radio works but I never turn it on, I want to listen to the music on my device through the car system but am too broke to buy anything

I just might have a picture of the radio label from a time when I had it out to install a Viper alarm.

 

[dave9]

Not replace the pickup head. That is a very low level signal that gets preamp'd to a line level signal before the amp stage of the stereo. The preamp output is fed to a mux or manual input selector switch, and that is where you want to sever the cassette input and substitute the BT module's output as the replacement input, or use a dual throw switch to switch between the BT module and cassette if you wish to retain use of the cassette feature, but then you need somewhere to mount the switch.

 

[XJohnDoe001x]

Dave, I think that I am going to put this project on the back burn. . . in the freezer. A used head unit from the junk yard is looking much better now.

I have too many other things to consider like connecting my Viper Alarm to my dash cam so that it'll start to record when activity is sensed and when I press a button on the key fob.

Also I want to put a switch in the power window system to switch between the normal key switch accessory power and straight battery power. I like to be able to use the windows without the key.

I already pulled the relay and put a jumper but there's a small parasitic drain from a LED, anyway this is a different post.