98 Chevy Blazer (2dr) won't start without first messing with the negative battery

cable? I am having intermittent trouble starting it. It will just click. The battery is charged and powers the rest of the vehicle, but I have to manipulate the negative battery cable for up to a half hour before the engine will turn over. I was recently told what a solenoid is. Could this be faulty and only work sometimes? And how would messing with the negative battery cable make the truck turn over? Also, I am unable to locate the solenoid. Is it directly underneath the battery? I haven't looked there yet. Thanks for any help you might provide.

If playing with the battery cable eventually gets it going, then I bet you have a bad connection right there. Take the cable off the battery and clean up both the cable end and the battery terminal. When they are both shiny clean,bolt then back together tight and you should be good.

If you want to do a better job, clean up the connection at the other end of the cable and then do the positive one too.