Solved: Aux Input Drops out Randomly, plus Bluetooth Adapters

jdoublehcubed · 08-16-2019, 01:25 AM

If you have ever tried to use the aux radio input and charge your phone via the dc outlet at the same time, you have probably noticed that the radio will randomly switch to a different input after a few minutes. If you swap back to aux, it will happen again, quicker, and eventually the aux input will disappear from your input options (temporarily) if you keep swapping back.

The problem in this situation is a ground loop:
car ground -> DC outlet -> phone -> aux input -> radio -> car ground

I purchased one of these 1/8" ground loop isolators and installed it, and I can 100% confirm that it fixes the issue:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I can also tell you that the reviewers mentioning an audio change are either deaf or have broken radios, because there is no audio change whatsoever.

On another interesting note, this will enable you to use an 1/8" bluetooth adapter. Trying to use a DC outlet -> USB powered bluetooth adapter is generally not possible because you'll get the ground loop situation described above. I own both of these and both work great:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

The firefly works in my wife's mini, and can be powered off the near-zero power output usb port that is built in next to the aux jack.

kidnees · 08-17-2019, 06:18 AM

I was having this exact same issue after recently installing AUX input in my E85. Thanks for posting this solution!

wdb · 08-17-2019, 01:14 PM

I have a Tunai Firefly in a couple of my vehicles and really like them.

08-16-2019, 01:25 AM	#1
jdoublehcubed Mechanical Engineer 96 Rep 1,025 Posts Drives: 2006 Z4MR, Imola Red Join Date: Jul 2012 Location: Anaheim, CA iTrader: (1)	Solved: Aux Input Drops out Randomly, plus Bluetooth Adapters If you have ever tried to use the aux radio input and charge your phone via the dc outlet at the same time, you have probably noticed that the radio will randomly switch to a different input after a few minutes. If you swap back to aux, it will happen again, quicker, and eventually the aux input will disappear from your input options (temporarily) if you keep swapping back. The problem in this situation is a ground loop: car ground -> DC outlet -> phone -> aux input -> radio -> car ground I purchased one of these 1/8" ground loop isolators and installed it, and I can 100% confirm that it fixes the issue: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 I can also tell you that the reviewers mentioning an audio change are either deaf or have broken radios, because there is no audio change whatsoever. On another interesting note, this will enable you to use an 1/8" bluetooth adapter. Trying to use a DC outlet -> USB powered bluetooth adapter is generally not possible because you'll get the ground loop situation described above. I own both of these and both work great: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 The firefly works in my wife's mini, and can be powered off the near-zero power output usb port that is built in next to the aux jack.
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08-17-2019, 06:18 AM	#2
kidnees Registered 2 Rep 3 Posts Drives: 2005 BMW Z4 3.0i Join Date: Aug 2019 Location: 08512 iTrader: (0)	I was having this exact same issue after recently installing AUX input in my E85. Thanks for posting this solution!
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08-17-2019, 01:14 PM	#3
wdb dances with roads 4732 Rep 4,096 Posts Drives: '07 E86, '02 996, '95 Seven Join Date: Jul 2015 Location: the perimeter iTrader: (4)	I have a Tunai Firefly in a couple of my vehicles and really like them.
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