Starter help

[mbaker5479]

So yesterday my starter decided to stop working so I had to have my truck towed home. I was able to get a new starter and installed it last night, along with fixing the two little wires that attach to the starter. Fired up first try no issues! Went out this morning to go to work and turn the key and just a click, tried 5-6 times with the same result. Checked all the wires and everything was tight. Ran some errands come home try it again and fires right up, turned her off, waited 3 minutes and tried again, just a single click, tried again and was able to turn over. No idea whats going on, buddy of mine says a loose connection but they are all tight, I've checked twice now! Any help will be greatly appreciated.

Thanks
Mike