1986 Chevy Truck Dead Battery

Electrical problem
1986 Chevy Truck V8 Two Wheel Drive Automatic 300k miles

This pickup hasn't had any problems in the past as far as the battery being kept up over time. The battery is new and alternator does charge at 14+V. When truck is running and the battery is disconnected it continues to run. However when the truck sits overnight the battery is dead. I have checked to make sure that the cab light goes off when the door gets shut. There isnt a bulb in the hood light. When the key is in the off position the fuel pumps do not continue to run. There isnt any other lights that stay on while the truck is parked. When the truck is shut off and disconnecting the negative wire on the battery there is a spark. This to me says that there is a drain somewhere. Was wondering if there is something that I have missed in the troubleshooting of the drainage of the battery.