Starter, battery, or alternator?

Ok, I have a little problem, and its an odd one.

Yesterday I went get some lunch for me and my boss. Traffic was horrible, so I was sitting alot, and my car does not charge well if the A/C is on and im sitting, it will usually charge fine, but sometimes when its reeally hot it will not charge right.

I heard a humming noise so I turned the radio down and at first I thought it was my fuel pump, but it was coming from the front. I looked at my voltometer and it was almost all the way down. So I revved it up real quick and got it back to normal. Now when I got back to work, I cut the car off when the voltometer was still kinda low, so I figured Id have to jump it, which I did. It was just clicking and would not turn over.

Then I got home, and when I went to leave, it would not start again. It would make a whirring sound. Im pretty sure it was the starter spinning, because it wasnt just a constant noise, it was "revving" like a starter would do. I jumpstarted it with the lawnmower and it went to my buddies house fine.

Then we left to go somewhere else, started fine. When I went to leave this place, it would not start. So we tried to push start it. It would not start the first two times. I went to try to start it again and it started right up. WTF?

Then I went back to my buddies house, cut it off, and then went right back to turn it on. Would not crank, just the starter noise. Tried to push start it, after one try, I turned the key and it started right up. Then I get home, cut it off, try to start it up again and it just makes the same noise.

I drove my moms car to school this morning and I just got home and went to start it. It started up without a hitch. Then I cut it off and went to restart it, and it just makes the noise. WTF?

The first time it wouldnt start, the clicking pretty much meant dead battery. The second time I jumped it, but it was making the starter noise. Third time tried to push start it, didnt work, then it fired right up, same thing forth time. 5th time, would not start back up, just now, started fine, but would not start back up again.

Im confused as hell.

I had it tested around the beginning of the year. The battery is probably around 2-2.5 years old.

And the battery is showing good voltage, Im pretty sure its the starter loose or screwed.

Ok, the alternator is humming. Alot. And it gets really loud when I rev it up.

I got it to start with a battery charger on it, then got it under the carport, cause its about to rain. And once I cut it off, it would not start up again.

Ok, so I grabbed the solenoid and I can move it about an inch any way I want.

Its like its not even connected to the starter.

Ok guys.

How the hell do you get the top starter bolt out?

Ok, I got it all out. The two screws holding the solenoid on had backed out and it was just hanging there. Im just gonna replace the whole thing while I got it out.