Starter Clicking

[Stout72]

Having a strange starter problem. When I turn the key to start the truck, the starter goes "click" but the engine doesn't turn over. After a couple of tries, it finally kicks over and cranks the engine just fine. Most of the time it acts like this, sometimes cranking on the 2nd try, the 3rd, 4th, 5th... Once in a blue moon it cranks on the first try like it's supposed to. It's been doing this on and off for about a month now. It sounds like the solenoid is engaging the gear with the flywheel OK, but the starter motor just isn't spinning up. Haven't had the chance yet to crawl underneath and watch while someone else works the key.

I've been commuting to work on the bike, so I haven't driven the truck much this summer. Would sitting for long periods of time be a factor? Maybe it just doesn't like being ignored for so long. It's a new starter, installed just last year. I don't think it's the battery, it has plenty of umph when the starter finally decides to crank over, and it's not charging that hard after the engine starts.

Any ideas?