I drove my truck last saturday morning and after running around doing chores i decided to replace the passenger caliper and brake hose. Once I was done and moved to the drivers side I jumped in the truck and tried to start it. I turned the key and nothing. So I hopped out and saw smoke coming from my starter. Fast forward 3 days and I have my new starter in and I go to crank it and it starts to crank, but it is not enough to turn the engine over. I moves the fan about 3 inches and then it rolls back to where it started. (The fan rotated counter clockwise if you are standing in front of the truck). Any ideas on what is going on?

 

Make sure the battery is fully charged and will take a load. Your local auto parts store should be able to test it for you. And check the cables at both ends to make sure they are not corroded and are making good contact.

 

I let it sit on the charger for about an hour, went back out, took the fuse/relay box off of it's mount and moved all the wires around. Jumped in the truck and it started right up.
It must have been a loose or partially corroded connection. Now on to fixing the AC compressor.....

 

The no crank will likely come back to haunt you again.
You did not really find the cause.