95 T-Bird - I need help!

I have had the battery and alternator tested - they both test out just fine. I replaced the positive connector on the battery after I found a little corrosion. It has been an on again, off again cranking process. Sometimes it will crank, sometimes it won't. When it decides not to start, it makes no sounds whatsoever - none - however the radio, clock, etc. never loses its memory. If the car runs for a little while and it won't restart - I can wait an hour or so and it will start right up - no hesitation. My next venture will be to check the starter - why, if the starter is bad, will it crank - and then after it runs for a little while it won't crank? Any help is greatly appreciated!

What engine is in it?

Sounds like the starter...starters do that sometimes..

Usually they go dead..and that's it...but sometimes the starter will have a little life in it, and hook sometimes.. I forgot the name of the mechanism in the starter..but it wears down, and sometimes you can actually BANG the starter with a wrench while someone is trying to start her up..and the mechanism inside the starter will hook..

It has a 4.6L V-8

Before replacing the starter be sure the connections are clean and tight on the starter. It just might save you the cost of a new starter

I checked all of the connections and they appeared to be tight...still had the same problem. I replaced the starter and all seems well. Thanks for the replies and ideas to help get me going again!