S4 verizon aux cable issues

[trongone1]

ok so my aux cable works great until i plug it into my car charger, when i do this it no longer reads the aux cable as headphones and it disconnects them and my music plays out of the built in speakers of the phone. when i unplug the charger it goes back into headphone mode and plays them through the car speakers. has anyone else had this issue? to sum it up it literally wont charge my phone and play through my car aux cable at the same time, but if i plug my samsung or apple headphones it doesn't disconnect i don't get it lol