Frogger dies after road trip? on 1993 Saab 900

someone told me that it doesn't recognize being in park because it's an automatic and that specific switch cannot be ordered anymore. It runs fine until you stop...then acts like a dead nail...but not like a dead battery...everything still works just won't turn over. Had it tested during this problem and all power was fine in all areas. Oh the starter was replaced also with every other ignition part.

Asked by for the 1993 Saab 900