you could try making your own pepper spray and coat your cable with it, or spray around the area as deterrent.
we had a persistent squirrel trying to build a nest under our eaves - kept coming back even though we'd knock down the twigs each day for a couple weeks.
Tried Critter Ridder - no effect, squirrel came back. Tried spiking the Critter Ridder with extra cayenne pepper. Still no luck
Finally, I found a recipe online - boiled a large onion, some jalapeno peppers and cayenne pepper (forget the exact ratio), strained out the solids. (don't rub your eyes while making it!!)
- sprayed it around the area of interest. Squirrel never came back.