Please help with wiring problem.

[SAVAGE907]

I have a sub hooked up in my truck. It makes a loud thumping sound usually when my truck shakes or I touch the cd player. I took the cd player out and I narrowed it down to a wire labeled as "battery +". Its really confusing me though. If I run my finger down the insulation on the wire I can hear my sub and only my sub amplifying the sound of my fingers running across the wire. And the slightest bump of the wire will send my sub into a thumping seizure. I think that I narrowed it down to the end of the wire that clips into the CD player. It goes into a wire harness along with a bunch of other wires and clips into pins sticking out of the back of the CD player. I can't see or feel anything wrong with it though. So if it's in the harness securely why would it cause my sub to thump if it's touched at all?

 

[mmbongo]

 

[SteveIII]

Im pretty sure this belongs in the off topic sub forum. Nothing to do with bass guitar