[rja]

When I plug my mp3 player into my aux jack and run it off the batteries, it sounds fine. However, when I run off of dc power from the lighter jack, I get a ton of noise....and it doesn't seem to be the hissing that most people here experience. It is more like a faint clicking noise. Does anyone know if a Ground Loop Isolator will help?
Thanks.

 

[sbl]

Seems unlikely to me. Could be that your power adapter is defective. Try listening to the player through headphones while powered that way and listen for the clicking.