3,5mm AUX not working in car - what could be the reasons?

[Bison of Sweden]

Hi all.
So, I have a brand new Nokia 7 Plus wth android Oreo (not sure if that matters at all) that Im trying to connect to my cars' stereos to listen to Music.

In car no 1: nothing at all. I plug it in, there's this static sound like you'd expect when connecting via analogue, but sound is not transferred from phone to car stereo. Nothing works.

In car no 2: works about every tenth time I plug it in.

I have tried switching Cables, using Cables from 3,5 to 3,5 and from USB-c to 3,5, and the same Cables works fine with an iPhone in the car. There are no issues when I use the headphone jack with regular headphones or computer speakers, that works as it should.

I'm getting very frustrated and would appreciate any help!
Thanks!
/Bison

 

[Rukbat]

Make sure that you have 3 pole plugs on the cable (1 ring), not 4 pole plugs (2 rings) - unless the car's Aux jack has a mic input - then make sure that you're using 4 pole (2 rings) plugs on the cable. Crossing the type of plug will cause problems. (Once in a while you don't have the plug all the way in and it works.)