Starter just keeps going?

[bennylava]

I'm having an electrical issue with my 87 TBI 350 truck. 2wd, automatic. For some reason, after you turn the key, the starter just keeps going and going. The truck doesn't get driven all the time. So a week ago, I went to grab a bite to eat and when I came out, the truck wouldn't start. I guess it also has some kind of dying battery, or perhaps an alternator charging issue. But I cranked on it for a little bit, because it sounded like maybe, just maybe it would start.

All was good for the first few tries at cranking the engine over. However, on the last try, I noticed that the starter did not stop trying to turn the engine over once I had stopped turning the switchkey in the cab. I took the key out, and the starter was still going. So I hurried and popped the hood and took the battery cable off. Luckily I managed to do this in time, before the starter killed itself. But now, a week later when I attempted to start the truck, the engine did not turn over and the starter just made a high pitched whine and span itself into oblivion. A good deal of smoke came out from underneath the hood. So my guess is that now this starter is probably dead.

I haven't had a chance to inspect everything yet, but I figured someone here would probably know what will make a starter just keep spinning after you stop turning the key. Any ideas what could cause this?