1990 E-350 460/7.5l

I went to fill up with gas this morning, turned the ignition over and I get nothing. It won't even make a sound, no click, no turn, nothing. I had a full battery charge when I first tried to turn her over, and slowly while I was trying Ignition, the battery died out. SO, I put some jumpers on the battery, and when I tried to start her up, All I get is a rapid "click" sound. A very rapid electrical "click click click click click" sound... BUT only when jumpers were connected to the battery. When I take the jumpers off, I get nothing, no sound, no turn. The battery is charged, but I try to start her up, it's almost like the starter is locked up and sucking all the juice from the battery. I'm stumped. I think it's either, alternator, starter, ignition coil? The funny thing is she doesnt even try to turn, it's like a dead connection... But when jumpers are connected it just makes a rapid "clicking" sound". Any Help?

 

Start with the basics. If battery has removable caps, be sure water levels are full.
Check cleanliness and tightness of battery cable connections-both ends.
Test battery voltage at rest. Check voltage while cranking engine, it shouldn't drop below 10 while cranking.