Ford f-150

Is the battery charged up?

Check gas pressure at rail to see if it's fuel related

Put in park

If not cranking and battery is good, check ur battery cabkes fir corrosion and to make sure they're making good connection. If all these things are ok, check ur alarm system it may be armed

If it won't crank, you may also want to check the solenoid (mounted on the firewall close to the battery).A bad solenoid (around $28) and/or corrosion on any of the wire terminals can be your problem, If installing a new solenoid, make sure the contact area on the firewall is clean and fresh of dirt, rust, or paint on the firewall, as this will make for a poor ground. NOTE: As in my case, if someone used a "quick connect" to repair the wire connection from the ignition switch to the soliniod thinner brown wire connecting to "post S", remove me quick connect and do a proper wire splice with factory or replacement connector.