[Shotimes] Starter problems

[David Nesbit]

I need some ideas.  A couple of nights ago I came out of a store, got in my 91
SHO, turned the key to start as usual.  The engine did start but the starter
did not dis-ingage.  I thought maybe if I put it in gear and move the starter
will dis-ingage.  This thing is sucking juice like crazy --voltmeter is
reading 10 and flashing ( I have digital gauges).  Shortly I hear a kind of
pop or clunk.  The starter is not longer engaged, voltmeter is now reading 14.
Everything else looks OK.  Since I am 45 miles from home I decide to get home
ASAP.  Voltmeter stays at or near 14, temp in OK, Oil pressure is good.  The
good news is that I make it home.  I wanted to see if it would crank again
(one can always hope).   All I got was a clunk  kinda like very weak battery.
I charged the battery overnight even though it did not seem all that bad.
Still get clunk.  I look in Helms for help.  I test the starter relay as they
describe.  It indicates that the relay is bad.  I replace the relay.  Still
clunk.  So I replace starter.  I turn key and the engine starts but the
starter does not dis-engage.  I quickly disconnect battery cable so that I
don't ruin another starter.
     So what can the problem be?  Ignition switch?  key lock?
Please help me with some input.
  Thanks,
David
94ATX&91