ipod/aux jack/usb power sounds like poop

my ipod is plugged into the factory 6 disc stereo aux audio port. i get a noticable amount of power, bass and volume loss when i plug my ipod's usb power cord into a 2 dock 12v DC adaptor w/ usb port, all plugged into the right side DC outlet under the dash of my 2010 taco. as soon as the cord touches the ipod housing, dont even have to fully engage it, this is present. whats up with that? ive tested the cord by replacing it with a direct 12v DC plug and its the same. save me oh wise electronics geeks! pardon the exposed cords. this is just temp till i figure out how to solve the issue and how i wanna route everything. it also makes removal easy.

ps: the garmin dash mount is a winner! doesnt move a mm. thanx for the tip folks.

 

I'm not familiar with the ins-and-outs of iPODs, but I know that audio can be sent down the USB cable. I wonder if when the usb connector is plugged in, the iPOD lowers the headphone jack level (e.g. down from a headphone jack to a line-out jack which is no longer an amplified signal). That may be by design or the iPOD may be "confused" because both the USB and headphone jack is plugged in.

Just some thoughts. Does it work ok if the usb is unplugged?

 

Not sure if this would be the case. I plug my iPhone into my computer at work all the time to charge it while I'm listening to music and I've got no problems what so ever.

 

running the AUX cord right next to the other cords may be causing noise. I would try separating the cords to see if that helps.

 

What is your output amperage on your car chargers? If the USB output on your splitter is less than 1amp its not strong enough to actually charge the iPod. If it is less, it may be drawign power from the iPod causing it to loose volume and bass.

Just a theory though.