OK, you also said that neg cable got hot, did the positive as well? Heat in a cable means one of two things only: the starter drawing to much amperage, or cable is not adequate in some way. Best first check was cable. Was replacement at least 0 as mentioned, and have really good ends? You can run both cables at same time as well. Next is checking out starter. Could try removing and try it with jumpers to a good battery, or take to a parts place or motor shop that can test it.
