Hi so I recently picked up a 2008 gmc 2500 6.6 with known problem that when you turn the key starter won’t crank, when you jump the fuse it starts right up. Have replaced the starter/solenoid/and fuse so far but none of that was the case. Have looked around no corroded wires or anything. Also have no power to ac fuse and my trailer breaks don’t work /show no output but haven’t even started getting into that yet. If anyone has any ideas I’m thinking maybe replace the fuse panel maybe something had fried in there? Also she’s at 300k miles.