2006 4.3/Auto Ext Cab Silverado. Wont turn over or start, just clicks. Help?

[NastyBuzzard]

Hey guys! Just picked up this 2006 Silverado 4.3/auto ext cab short bed work truck.



Previous owner said oil pressure all of a sudden dropped to 0. When that happened he killed engine and pulled off on side of road and had it towed. When he tried to start it again it wouldn't do anything but "click."

I bought it and am trying to figure out what is going on with this thing. It wont even attempt to turn over, when you twist the key it clicks, loses all power it acts like then powers back up and then you try again and does it again. Yes it was a good batter . Any ideas?

Check out the vid of symptoms.