1987 Chevy Corvette Dead Start circut

The car had no previous problems. A battery charge was needed this spring. When the key was turned the dash lit up but would not crank. The next day the car started twice with no problem now it is dead!
All is fine at with the starter but there is no juice to the solonoid. I tried to do a scan and kept getting a message on my scanner that it was not plugged in?
I have been looking for wiring diagrams with out much success. Could this be associated with the ignition switch / anti theft circut?