On my last truck I knew the starter was going bad when it took longer and longer to start before it finally wouldn't start until I tapped on the starter, ultimately wouldn't start at all..
With this k1500, I never had the slow starts, it just wouldn't start one day. Tap of the starter and it finally started. Ran fine for a couple days, then again wouldn't start. Tap on starter, fired right up.
It's just odd that my 2 experiences were so different. Which one is more typical?