I have created a path representing the side profile of a character's face in Illustrator, and would like to use 3D Revolve to create the other side view/generate a 3D version of the face. However, this is not working, and I am unsure whether Illustrator is even the right program to use for this purpose.
So I'm not exactly sure what you're trying to accomplish. If you want a 3D object, go with a 3D program and there are dozens of tutorials that will tell you how to make a model from a photo. If your making an illustration of some form, then it would be easier to go back to basic drawing techniques and fill in the visual information one piece at a time - illustrator works great for that. I've never been real happy with AI's 3D feature since it always tended to be resource Intensive and really only makes a 2D model with some pretty basic features. I think most (even FREE) 3D apps out there will do the same with far fewer resources and you have a model you can load into photoshop to make the final comp.