stang9150

I have a 94 gtx with a 587 motor.I just put the motor back together after sitting for 6 years.I had the battery hooked up and was turning the motor over It cranked fine for about 10 seconds,then it sounded like the starter was intermittent,buzzing,turn over buzz,turn over.Now it will not do anything at all with the starter button.I have a hot battery,both fuses are good,I measure 12 volts at the solenoid,I can jump the solenoid and nothing happens.I put 12 volts right to the starter lug and the motor will turn over fine,so appears the starter is good.Is it common for the solenoids to go out?Funny that it worked fine then just quit and now the ski acts like it has no voltage at all.What connections could I check maybe I got a bad ground somewhere.