General Aux Lead Voice Issues

[FiatFiasco84]

Hello! I feel like I am going insane so any help welcome!
My Bluetooth has stopped working in my fiat 500. In the meantime I’ve been using my aux. Now I have a aux lead that I used for music and also it allows for voice.
As I’m now using it a lot I decided to get a new lead that splits and also has a charger so I can charge and use the aux… however this then doesn’t allow for voice! It will only play music from my iPhone and not play my calls out loud. I don’t understand why not?? It’s literally the same sort of cable… just with a charger as well. What am I doing wrong? Why can’t I chat and charge?
I’ve attached a couple of pics of the aux I normally use. I don’t think there is anything fancy about it and don’t understand why a new one won’t work. Any ideas?!

 

[John202020]

Welcome try using a separate charger in the power socket to charge not the USB port?
The Bluetooth module is known to fail and if left can lead to a flat battery if the cars not driven every day as it constantly draws power the fix it to physically unplug it, passenger side rear quarter panel.
Also a well known issue is the car will need a new engine earth strap if its not had one.

 

[FiatFiasco84]

Thanks. I’m using a separate charger port to the USB one
I just don’t understand why one aux cables allows me to do voice calls but a aux/charger combination one doesn’t.

 

[FiatFiasco84]

Thanks. I’m using a separate charger port to the USB one
I just don’t understand why one aux cables allows me to do voice calls but a aux/charger combination doesn’t.

 

[John202020]

Thanks. I’m using a separate charger port to the USB one
I just don’t understand why one aux cables allows me to do voice calls but a aux/charger combination doesn’t.

I think it's a conflict between line in jack plug and USB communications if you cut( or cover with tape) the communications wires in the USB plug to make it charge only it would work

 

[FiatFiasco84]

I wish I knew what any of that meant!

 

[John202020]

On the USB plug the two inner pins are the communications pins the two outside ones are power