so the other day i dropped a belt pulley. While I was at I, I thought Id replace my t-stat, seeing as it was faulty. I disconnected my battery, drained my cooling system, replaced the t-stat, and put the idler pulley back on, in addition to the belt. Reconnected my battery and turned the key. Absolutely nothing. There was no crank, just a clicking noise. I don't think my starters bad it was replaced about 3 months ago... thanks in advance for any help.

 

make sure battery cables/terminals are clean and tight.
tap on side of starter with a hammer.
try jumping it.

 

Drained battery, bad starter, bad starter solenoid. New starter doesn't mean perfect starter. Things do go bad, specially if your truck has needed to crank too much to turn over. Probably under warranty anyway. Try a jump first.