does anyone no if there is a solution to eliminating alternator whine over speakers on aux input only. the whine is horrible and increases. i can hear it all the time on auxiliary only even with volume down . thanks!!! 2009 cooper S

 

There are two possible causes.

1. This is due to very poor grounding in the AUX jack, you will need to open things up and reground the AUX jack and even then you may still have some whine. But it should be greatly reduced.

2. Ground loop generated by having two different ground potentials when the item used with the AUX jack is also plugged into power like the cigarette lighter. To check this run the item with it disconnected from power and only running on its own internal battery. If the whine is drastically reduced then it is a ground loop problem and can usually be rectified with aground loop isolator.

 

thanks Schatzy 62! i was wondering about the aux grounding ,but i didn't know where it was? it's def not a ground loop issue as i hear the noise with nothing plugged into the aux jack and immediately when i switch to aux on the stock radio deck. i will check that and appreciate your reply. i was also wondering about an inline power noise suppressor but was unsure if it would work thanks again

 

snikrep1, what device are you plugging in?