The short answer to your question is - There is not much difference between Soul (Atman) and Kundalini. They are just the different names or perspectives of the same principal. To be more specific, Kundalini is a major part, but not complete, of awareness or the Atman (Sanskrit) that we call as Soul (English).
Both of you have asked many questions on the Nature Of Atma (Soul). Firstly, Atma (Soul) is a spark from the Supreme Lord Krishna who is the Paramatma, and it has no feeling for itself, but, it makes the senses to feel something. Atma (Soul) can be perfectly compared to electricity. .