I have a '98 discovery and everytime I turn the ignition it disables and the alarm beeps and I can't start the vehicle. I've figured out if I turn the key in the door 5left 5right 5 left 5right and open, it will start. Also when it sits there is a random knocking noise coming from under the hood and eventually will drain the battery. This is my family's only means of transport at this time and were hurting for money. Please help. Thanks

 

While it is making the knocking sound, unplug fuses on underhood box to stop knock, then you may know where drain is coming from.