Won't start troubleshooting

[farside847]

Looking for pointers. Drove my truck for about ten minutes. Started right up. Turned it off for 20 min, then it wouldn't start. Just a single click. Later I tried it again an it started and I got it jome. Three weeks later I got paid and took the battery in for testing. It wouldn't hold a charge so I put a new one in. Started right up.

The next weekend it started right up and drove it for 20 min. Stopped for a while then it wouldn't start. Single click. Waited and it still wouldn't start. Tried to jump it and same click.

So, since the jump didn't work I am guessing that the battery and alternator is ok. Maybe a bad starter? Bad starter solinoid? Bad cable? Would love some pointers.

Thanks!!!