Hey if you are still around any chance posting a picture of this. Pardon the pun but this reads like stereo instructions and I learn visually.I just wanted to add a note to this thread on my experience.
I had very similar symptoms and even work with Jonathan on using his modified connector to try and resolve it.
Ultimately, (I also let Brian know who sells these connectors on ebay) the solution was:
* connect the black wire from the connector to the two shield wires (the two sheild wires are connected one to the DIN shield and the other to the RCA sheild)
* do NOT connect the black wire to any ground, rather take the 3 wires and I shrink wrapped them together
For my car, it seems that the ground is addressed already through the DIN shield of the connector back to the amp, so connecting that all up to ground eliminated what sounds like a ground loop.
Thanks for your time
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