Problem starting my S-10 truck

I have a 96 2.2L S-10. About a year and half ago, my truck would sometimes not start. One day it would run fine, the next it wouldn't even turn over. I had the battery, alternator, and starter replaced. Now, I can't get the starter to crank. I had the battery and the alternator tested and they are fine. We couldn't test the starter because the engine wouldn't crank. I had to pop the clutch to get it started. Anyways, the automotive guy at autozone said it might be the ignition switch. Should i try this? How hard is it to change this part out?
Oh yeah, about a week ago, my sercive engine soon light came on, could it be a bad connection between the ignition and the starter? Any help would be grateful.

I Would test the ignition wire to your cilinoid (purple?)hook up a volt meter and have someone turn it over should be aruond 12

I probably would get one of those circuit lights see if you have current going to the starter, touch probe to to the bolt and not the nut on the starter, make sure you don't have one of those starters that have extra bolts for different kinds of cars, one of those generic starters, if it has extra connections, you might be hooked up to the wrong bolt, to ignition, etc...

P.S. I'm not a mechanic, but seen a mechanic hook up some car to a generic starter, and tested with a circuit tester, figuring out the starter had extra bolts for older cars systems, and another for newer cars, depending on which bolt you connected the ignition to, if I remember right, the battery could only go to one post, just check to see if there are other bolts on the starter that look suspicious, if you had started the truck with the new starter in the past, then its hooked up correctly, might just reclean the starter connections, and check the fuses, etc...I believe auto zone has free booklets and keys for checking your engine codes, it might have something to do with your problem, etc...

If there is no sound check ignition switch.