04 Ford F-150 won't turnover

If the starter motor won't crank, I'd have to check starter wiring circuits. Make sure battery has a full charge and all battery cables and connections all good, no voltage drops. Usually two voltage circuits at the starter, one comes from the battery hot all the time. The other goes hot with key in the crank position and is wired through the neutral or clutch switch depending on the tranny. You may have starter relay, I haven't looked at your wiring yet? The starter motor usually grounds through the engine block. Another thought might be your antitheft system causing an issue with starter? Usually, if the starter is functional and the engine isn't seized, I can get the starter motor to crank, but, that doesn't mean it will start, if the security system is involved, even if you get it to crank, it still isn't going to start. When testing at the starter, make sure tranny is in park or neutral and the parking brake is set. Some makes and models if battery voltage is lost some systems may have problems? I try to recommend using a memory saver or something so the memory isn't lost when taking battery connections loose. Gasoline engine?

To make sure, it's not the security system, disconnect battery and inspect battery cables, before re-connecting, turn ur ignition key to on position, now connect battery and try it. If it still doesn't crank, go under truck with ignition key in off position, jump, the 2 screws at the starter where cable comes in from battery and the other small screw where the signal comes in and see if it'll turn over. If it still doesn't, replace starter. If it does, trace signal from ignition switch