Originally Posted by BradWhite
Isn't this the same type of shielding we're referring to regarding these cables?
I'm not trying to argue with you, believe me my knowledge level of automotive wiring is worse than a two years olds. But shielding, as described above, make sense to me.
Yes, that is shielding, but if the wire you're using as the shield is grounded to the car ground, then it's going to experience the same noises as the ground. So if the ground sees a spike, the shield will see the spike too, since they would be at the same potential to each other at all times. Thus, the shield is not truly electrically isolated from the ground wire it's supposed to protect. It would be effective for high frequency noise, but not all types of noise.
In theory, you could wire the ground shield to the earth by dragging a wire on the ground and attaching the ground shield to that. But who would do that? :)