So, I actually got hold of a PIE audio ai-net adapter to inject a line in over the radio on my alpine premium system, and it works as intended/designed.

Now, my actual question is: does anyone know a good way to "force" the adapter to take over audio all the time, even when there isn't an audio signal/volume on the line-in? This is to permit me to do handsfree bluetooth calls with the bluetooth module I installed, however without anything playing through the speakers the radio takes back over again.

And yes I know I could just install an aftermarket head unit or Joying unit, but dammit I'm close and had already started when monkeybrains posted his write up the other day .

adapter I'm using in case anyone is interested: https://www.ebay.com/itm/265519714312

Does anyone with one of these modules happen to know a way to do this?

 

Does your bluetooth module have a mute signal to go to the car stereo when making a call? You can find all the necessary wiring connections under the centre armrest/console.

 

Do you use the CD changer? I just connected a RCA cable inside my CD changer and connected a DAB/Bluetooth adapter to it. Works perfectly and now I can play music from my phone through Bluetooth instead of using CD's

 

Thank you both @NorXKR and @dibbit for your suggestions, my bluetooth module does NOT have a mute function (its a very simple 2xrca + 1 3.5 jack microphone deal that takes 12v power) or I would take that advice; no, I have the very simple problem that the PIE audio adapter requires an audio signal to "hijack" the line in to the radio, when you are on a phone call and talking, no audio plays through the speakers so the radio kicks back in - I am just trying to figure out how to "tell" the PIE audio device to always take over audio. Its probably a simple jumper/solder/switch on the PCB, but I am not much good at logic analysis. Right now I am contemplating Monkeybrains' solution with the Joying head unit and his custom bracket, OR just wiring a bluetooth module straight into the amp I installed and bypassing everything in the car.