one thing to check as well, the cable connection to the solenoid from the battery, I had a similar problem up until 2 weeks ago: initial crank was just a click, jump the solenoid across the big terminals so the starter spun, then it'd crank with the key
baffled the heck outta me, turned out the cable had broken inside the crimped area, it was "kind of" held into place (strong enough to take on and off the starter, until I moved it "just right" hooking it back up and it popped out)
spent over an hour going from store to store to find a 4/0 cable end
baffled the heck outta me, turned out the cable had broken inside the crimped area, it was "kind of" held into place (strong enough to take on and off the starter, until I moved it "just right" hooking it back up and it popped out)
spent over an hour going from store to store to find a 4/0 cable end
