Audio Screech

Mick288

Active Member
Aug 3, 2009
434
1
Lisburn NI
So i managed to get one of THESE for a fiver.

Now, my iPod/AUX works perfectly, but when i use this cradle, and the ipod is sat in it with the power connected, it makes a hideous screeching noise through the speakers.

It gets louder as the revs rise.

What is going on, and how do i fix it?


Cheers guys
Mike
 

Mick288

Active Member
Aug 3, 2009
434
1
Lisburn NI
Its 100% serviceable.

Ive heard of alternator whine, and i believe i may have it here. But it only happens when my iPod is charging through the cradle.

The cradle plugs into the 12v socket and has 2 things it does. It charges, through a built in iPod connector, and it takes audio through its own small tidy AUX lead, and puts it to the headunit by plugging my AUX lead into the cradle next to the 12v plug.

Audio works fine when the iPod isnt in taking power through the cradle, but it whines like hell when it is taking power.


Any more ideas?
 
Feb 26, 2009
5,275
1
Wolverhampton
I have a similar thing going on with my Android phone. You should find it sounds fine with the engine off even with the device taking power?

I've come to the conclusion that SEAT earths are shocking. A few people on here have bought grounding kits, and it's what I was going to do to resolve the issue. It's basically really thick cables connected to various points on the engine, alternator, chassis, head unit etc, and puts everything at the same earth point. Then the phone charger would be connected to the same earth, and fingers crossed it would resolve the noise. You can buy ready made kits, but I was just going to make my own.

For the time being I simply run the phone off the battery and it's fine.
 
Last edited:
Feb 26, 2009
5,275
1
Wolverhampton
Take a look at the following post, it might be of help;

http://www.seatcupra.net/forums/showthread.php?t=283987

There used to be a groundingkits.co.uk, but while the website still works it is completely empty. There's also a few Ebay bits and bobs. I can't find any pictures though.

I think the best one to fix this particular problem is to put a nice thick bit of wire between the cigarette lighter shell and the head unit shell, and then put both to the chassis.
 

dgjdrummer

Part-timer
Nov 5, 2011
1,310
4
Wrexham, N. Wales
You state that the AUX lead is actually built in to the charging device? It could be running AUX and power leads parallel causing the whine as the drawing of power will interfere with the audio signal. If it stops when the engine is switched off though then it's most likely alternator whine.
 
Feb 26, 2009
5,275
1
Wolverhampton
You state that the AUX lead is actually built in to the charging device? It could be running AUX and power leads parallel causing the whine as the drawing of power will interfere with the audio signal. If it stops when the engine is switched off though then it's most likely alternator whine.

Sounds reasonable, certainly in my case with the engine off it was perfect.
 

Mick288

Active Member
Aug 3, 2009
434
1
Lisburn NI
So, if its alternator whine, connect an earth to both the 12v socket and the back of the headunit somewhere, and run them to ground somehow?
If not, then do something with the cradle?
 
Feb 26, 2009
5,275
1
Wolverhampton
I think you'll also need to earth the alternator, otherwise that'll still be floating. And obviously the battery earth needs to be sound.
 
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