As red58 said, normally that wh/red wire would run directly to the coil, but since you have another wire off that same starter post that goes to the coil, electrically it's the same thing.
I can't access your pics, it's asking for a password.
That braided wire IS the ballast resistor, you won't find one in the cab somewhere. I don't know why the designers at GM used firewall mounted resistors on some models, and resistance wire on others but that seems to be the case.
