2005 Saturn Ion 2 , 5 speed.No crank , no start.

No crank , no start , no gauges , no link to obd2 scanner. No power to crank relay , no power to fuel pump. Did key relearn, cleaned all ground wires, pulled ecm and bcm , inspected both looked fine , reinstalled. Checked all fuses and relays inside and out under hood. Decided to recheck fuse from battery on the ecm wire , it was corroded 12.6 going in , nothing coming out. Cleaned contact points in fuse holder ,tightened them up , put fuse back in , she fired up with all systems working. Be sure to check the ecm wire fuse from battery in the trunk , just because it's a good fuse does not mean it's connected , the contacts in fuse holder must be clean.