96 Blazer is having problems starting

I have a 96 Blazer with a 4.3 engine which won't start. The battery is charged and there is gas in the tank. When I turn the ignition to start, I hear a click and then nothing. It isn't even turning over. With the ignition in the on position, I can hear a slight hum which I assume is the fuel pump. So, I don't think that the fuel pump is the problem. Once in a blue moon it will start and run fine. If it turns over it will start. Any suggestions? Thanks

Check, clean, and repair if necessary, the connections at both ends of both battery cables and the body ground wire.

I will check all of the connections. However, the headlights, radio, dash lights, and buzzers do come on so I think the problem may not be the cables. I'm not much of a mechanic so I will check them anyway. But, could it be something else?

All of those items require far less current than the starter does. A connection may be good enough for those things to work, but not allow enough current for the starter to operate. Does the brightness of the headlamps change significantly when you try to operate the starter?

Well, ithe headlights are not dimming when iwe try the starter and I did clean the battery connections but couldn't get to the connections to the starter. There is a pretty hard click when we do try the starter. Any more ideas? And, thanks for your info so far.

Try jumping the battery. I had a '95 S-10 that had the same problem, turned out the battery had a bad cell and wouldn't crank. If that doesn't work, while someone is holding the key in the start position, give the starter a good rap with a hammer and see if it cranks. If it does, you need a starter.

If the connection at the starter is poor, corroded, loose, etc, it will cause what you are experiencing. The solenoid could click without engageing the starter motor. The fact that the lights don't dim when you try to crank, indicates the starter motor is not engageing. Check all of the connections at the starter before you jump to conclussions.

new starter and solenoid, GM only sells it as one package, 170 bucks brand new.