I would like some tips on how to cut the coil feature out of the block. I have included the file. I thought the split command would be it but was not able to do anything with it.
You are going about it all wrong - you have a single solid.
What about the voids between the strands?
This will give you a bit to think about for your next try.
Give it an honest try before looking at this file to see what changes I made.
I figured it out for the shape of the cable and fixed that to coil from one-piece sketch. When I click on Combine command, it comes up with a message: "Could not combine bodies. The part must have at least 2 solid bodies." But it does: a coil and a block... although when you highlight the coil it looks like it is just surfaces still..
Attach the file here.
The Combine isn't needed - the only reason I used it is because you were going about the problem the hard way.
All you really need is a block and then Coil-Cut. One Extrude feature, one Coil feauture, in that order.
As I said originally - I would do it differently.
But since I did trick you with your original file, what I did was
edit the extruded block and select the New Solid icon.
This made two solid bodies in one part file - your Coil as a solid body and your Extrude as a solid body.
Two solid bodies - that is why Combine-Cut worked.