Confused

Yesterday I posted I had a problem starting my 240z. I received a reply (thanks) that stated I should check the 10 gauge wire that connects to the positive battery terminal and goes to the starter. Problem is that I do not have have a wire going to the positive battery terminal, but the positive battery cable. This cable is connected to the starter along with a very small wire (do not know the gauge) which I believe is probably to the ignition. Please note that this little wire is coming out of a harness. I figure this wire is correctly hooked up because I have gotten the car started before in this configuration....however, now I can not get anything. Go figure. There are not many wires going to the starter. You have a negative battery cable, a positive battery cable and this little wire.....and a two prong connection to the starter(i can not think where this two prong connection is coming from....will get back to you all later with that info)