So i go to start my truck tonight and it wont turn over. Just a single click when i try and turn it over. Battery has 12 volts and connections for the terminal are clean. Tried knocking the starter with a hammer and did nothing. Could the starter be done? Drove the truck a few times today and no problem but now it wont turn over.

 

Check the connections on the starter.

 

1.Try turning on the headlights and trying to start it. If it goes Click and the Headlights go out then you have a connection problem. I would start with the Battery and its Connections first. 2.If you have been working on the Starter and have had it disconnected from the Battery or Ground then that might be a spot to look also.
3.Have you tried to jump the Battery off and start it that way?

If all else fails, check the tire pressure of the right rear tire. J/K