2000 Chevy Impala car wont start

Please be advised my vehicle was an ignition switch on dash. I had the 3800 eng. My father had a buick with same 3800 eng. Both autos had same sympton of not starting. No juice to engine (ie eng would not turn over) after much tracing of wires and experimentaion I replaced the starter switch at the ignition--problem solved hope this helps someone.