Ground Loop Filter Install in Mazda5 GT + Nav

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Mazda5 2008 GT White
Peripheral PGLI Ground Loop Isolator Noise Filter install in 2008 Mazda5 Grand Touring with Navigation

Due to the unbelievable high frequency noise generated while listening to an AUX input when any 12v device is plugged into the car battery, I installed an inline ground loop noise filter at the 3.5mm plug. I did not like all the wires all over the place and placed the 3.5mm car connector and filter behind the dash panel. I found the filter slightly deadened the high frequencies, so using a splitter there are two plugs to pick between -- an unfiltered plug and a filtered plug depending on if the device is also plugged into the 12v socket at the same time. While I was at it, I put in some strong magnets under the gear shifter dash panel (do this at your own risk!) to hold either device in place while driving, but is still easy to remove and hid in the glove-box when parked. It was fairly easy and now I can plug in my Ipod or XM My FI without interference.
 

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Ground Loop Filter Install in Mazda5 GT + Nav continued

Ground Loop Filter Install in Mazda5 GT + Nav continued with more photos
 

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Just bought the same GLI. I like the idea of hiding it behind the dash panel but don't like the idea of wires just coming out of the panel. I'll probably just stick with using it on the outside as I also have use for it in multiple vehicles.
 
Is that a stock Mazda Navi?

We opted not to get Navi in our M5 GT, but we will need to get something in the near future.

michael.
 
I have the same problem with listening to my portable DVD player while being powered by the 12V socket. Is this considered a defect? Are there other options out there?

Thanks!
 
Has anyone tried popping up the hood, and filtering the output of the alternator?

Some electronic devices are going to be more sensitive than others... go to your car parts dealer and ask for a filter for the alternator - it exists.
 
Another Option

Had the same problem with my Griffin FlexTune iPod charger cradle. Hummed like crazy. Called Griffin to complain and they explained the ground loop issue. Griffin makes an aux in cable with the ground loop isolator built in - cost me $13 at Amazon and fixed the problem completely.

BTW Mazda has a TSB about this that says "not our problem".

- Stew
 
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