Alright, I just replaced the alternator about three weeks ago, when I try to start the engine I get the clicks but no crank at all. It just happened overnight. One day it cranks on the first turn of the key and starts right up, the next day only clicks. The battery was tested and is good. In fact when I put the battery back in it started up, but then after turning it off back to the same thing. Lights work, etc. Oh, when I try to start it I get the clicks and also the lights come on, and the windshield wipers come on. I tried to jump it and it started right up. Help... I'm not sure where to go from here.

 

I would inspect for a poor/rusted/corroded connection at either the battery or the starter. Its perfectly normal for it to be at the battery, it can power the acc but not the starter motor. Also, look for poor grounding. You may also want to have the starter tested, if you dont find the problem in the connections.

 

Check the negitive ground sometimes they come loose or just corrod. And like the previous reply check the starter.

 

I should say check the neg. to the block it could be loose or corroded!! But also check all connections as something could be loose.