As some of you may already know, I'm a guitarist.

I own a jackson kelly, ibanez rg, ibanez acoustic and squier j-bass.
I have a line 6 spider III, use first act picks, and I have a planet waves cord.

That's where the problem is. My cord.

I plug it in to my amp. No problem

Plug it into my guitar. No problem.

Play a few chords. No problem.

Move a nanometer. Problem. Big problem.

The amp starts screeching.

Sure, It could be the amp.
Try another cord. Works fine.

My fucking cord causes my amp to make the most unholy noise known to human-kind.
What the hell?