Digital Sandwich’s Glen Faught shows how you can not only make cables and cords dynamic, but also how to attach them to objects so that it will move and react when the object that it is attached to is moved.
A quick how-to on connecting dynamic splines to animated objects in C4D with a Constraint and Spline Dynamics Tag
To show this, Glen sets up a dynamic guitar cord that moves and reacts naturally when the guitar gets moved around in the scene. By creating a spline in Cinema 4D, making it dynamic, and then using a constraint tag to attach it to the objects Glen notes that the basics of the processes is fairly simple.
Check out the tutorial for Connecting Cables Dynamically to Objects Using Dynamic Splines in Cinema 4D here for the details.