F150 wont start don't even get lights or anything battery good but nothing else works

What year F-150 ? Do you know how to test automotive electrical circuits ? Find a electrical distribution diagram at http://www.bbbind.com/free_tsb.html Enter vehicle info. year , make , model and engine size . Under system click electrical distribution , then under subsystem click power distribution . Click the search button ,then the blue links one at a time . Start at the battery , with a volt meter ,what's the voltage . Then check main power feeds to power distribution (fuse /relay) boxes . Under the hood , inside the vehicle etc... The first diagram shows two main 30 amp fuse in the ( BJB ) one supply's B+ to the starter relay an if you look down about 5 or 6 diagrams you will A goes to the ignition switch. The other 30 amp fuse powers the PCM power relay . Both of those if open could cause your problem . If these are ok keep looking at main power feeds etc....