You aren't clear on what you mean by "connecting it to my truck". Did you install the starter and connect the wires properly or are you trying to test it off the engine? If it's on the engine, disconnect the larger battery cable at the starter, then see what happens. Disconnect the negative cable at the battery while you're wrenching on the starter so you don't make major sparks. Once the battery is reconnected, you should get a rather loud clunk from the starter when you turn the ignition switch to "crank". If you do, most likely the starter drive is defective.
What was wrong with the old starter? Was it doing the same thing? If it was, suspect a cracked flex plate. Remove the starter or the inspection cover on the bottom of the transmission and try to turn the flex plate by hand. You can also put a mark on the flex plate, then see if it turns after you try cranking the engine.
Thursday, February 6th, 2014 AT 9:16 PM