playdirt

I have 3 other Chevy pickups all with 180,000-227,000.All have been great trucks except this one. After the last time it was driven apparently the dash lights stayed on after key was pulled killing the battery.The dash had been acting up so it was sent out and had it repaired.A new battery was put in with rebuilt dash.Turned key to start & nothing happened,no click nothing but the dash lights stayed on & wouldn't turn off until I disconnected battery.So I installed new ignition switch along with key assembly.No lights until I tried to start.Lights came back on & wouldn't shut off until I pulled start relay,then they go off until try to start again.Pulled start relay & installed jumpers.All lights went out.Tried to start again & heard start solenoid pull in & made bang noise like it had pulled in.Crawled under truck & jumpered starter with screw driver.Spun right over but no start.Tried installing under hood relays from an 02,didn't make a difference.Once I try to start, the underhood relay stays pulled in until I pull it,stays disengaged until I try to start again & just repeats.Any Ideas ?