1997 GMC Sierra 1997 GMC 1500 won't turn over

The truck gradually took more and more key turns and fiddling to start. At times it wouldn't start at all and was incredibly frustrating but after 15 minutes of looking in the engine(and not finding or doing anything) it would magically turn over and start. Someone suggested the park neutral switch, another suggested the starter. I have replaced the park neutral switch and had the starter tested(turned over quite easily). Could I have installed the park neutral switch wrong? Before if I pulled the park lever towards me and turned the key it started. Now I don't get anything and I believe I hear a clicking noise in the engine bay. A friend suggested the fuel pump tonight which I will check tomorrow. Any ideas?