Originally Posted by DFlintstone

It does sound like the starter, the way it "faded". Maybe go under and give it a good whack with a hammer and try it. If it acts different that might be inlightning. Or even whack it while someone holds the key over on start. If that worked that would point to the solonoid not making good contact. Be careful! (Of course)

A couple of times guys swore the terminals were clean, then actually had the ***** to post up later that I was right after all. ;

Battery gasses have a nasty habit of helping a thin, hard crust form on the bat post's and clamps. They can look pretty good, but that micro-thin layer is a surprisingly good insulator. SHINNY! Lead is what you want. I use a pocket knife, (gently), for the insides of the clamps. For the posts I might use one of those post cleaner wire brushes, but still scrape it with a blade. If you have a condition where you have power, (dash lights ect.), then when you hit it power goes out altogether, that's a common result of a layer of oxidization there. Btw, a half *** connection could be expected to get hot during cranking, or while it's trying. Cleaning those is something to do now and then anyway, so if you are having starting problems, you might want to make sure you have bare lead on lead. Might save you some grief!
Also if any connection is getting warm, there is resistance there.