Background Hiss when Iphone 4s Is connected to Car speakers.

[Guest]

This is one of the weirdest problems ive ever encountered and ive been tackling this problem for about an hour now. I dont even know if this is even the right section of the forum, but this forums my last hope.

Right when my Mum plugs her phone into the car speakers using the headphone out with an aux to aux cable. Music can be played, but there is a very obnoxious  hissing sound in the background. This can be heard at what ever the volume on the car is set to and what the car is set to.But the one thing thats confusing me is that i have exactly the same phone as my mum and it doesnt make the sound. The sound cant even be reproduced in my deskspeakers or any headphones using her phone.

Ive tried multiple things, such as
Turning the phone off and on
grounding out the phone in a hope to discharge any static electricity
Changing the cable (yeah i knew this wouldn't do anything but it was worth a shot)

Can Anybody help?

Thanks in advance.
 

[Tomtom565]

We had this problem when we got our new Focus. 

Exactly the same as you, both myself and my mum have a 4S and whenever I plugged her phone in it wasn't there, when I plugged my phone it it was. My carrier allows us to swap our phones for another one (Same model) withing 30 days of taking a contract. We just swapped my phone for another 4S and it was all sorted.

Its a small isolated issue, if you can get it swapped out for another unit.

[Guest]

We had this problem when we got our new Focus. 

Exactly the same as you, both myself and my mum have a 4S and whenever I plugged her phone in it wasn't there, when I plugged my phone it it was. My carrier allows us to swap our phones for another one (Same model) withing 30 days of taking a contract. We just swapped my phone for another 4S and it was all sorted.

Its a small isolated issue, if you can get it swapped out for another unit.

That cant be done its only a slight issue so my mum wont be inclined to getting a new phone sent to her. Is there any thing else i can do?

[micedits]

I know this is slightly unrelated as it is not in a car but sometimes a low buzzing is caused by a bad earth connection, however that shouldn't be the case in a car. 

[Guest]

I know this is slightly unrelated as it is not in a car but sometimes a low buzzing is caused by a bad earth connection, however that shouldn't be the case in a car. 

Yes that what i thought is was at first but even placing the phone on the bare metal inside the car to create a better ground made no difference. 

[Tomtom565]

That cant be done its only a slight issue so my mum wont be inclined to getting a new phone sent to her. Is there any thing else i can do?

 

It could also be as simple as a fault in the head unit.

 

Or you could try using a ground loop isolator although that would look pretty ugly in a car  :D

[Guest]

It could also be as simple as a fault in the head unit.

 

Or you could try using a ground loop isolator although that would look pretty ugly in a car  :D

I do notice that i get the noise when i have my volume not on full on my phone when its connected.

[ShearMe]

The fault is in the phone's 3.5mm jack, no doubt about it since you've got two of the same phone to compare.