My 2000 F150 has juice but won't start.

check battery voltage, should be 12.4vdc. If battery is good and still won't turn over, Make sure nbattery is fuly charged, should read 12.4vdc minimum, Check all battery cables for corrosion and make sure they're tight. If all cables are ok, check for voltage at the starter solenoid small terminal. If voltage is present and still no crank, replace starter. If no voltage present, trace back to solenoid and starter relay

Don't know if this will help but i had same problem there is a unit above spare tire i replaced and it was ok they rust up hope it helps