Okay, I got the 24VDC batteries (2x 12V) today, and got the same result. So as soon as I was about to give up, I turned the black little handle ontop of the gear box to the far right (you can see what I'm talking about here: **broken link removed**) which seems to lock the wheel, however, when I applied power to it this time, IT TURNED!
When you turn the black lever to the left, it allows me to turn the wheel with my hand, but if you turn it to the far right, it locks the wheel, so it would seem natural that you shouldn't have it turned to the right if the wheel appears to be locked, but that's not the case here...
So that was one nice discovery, however, there was 1 more to discover. Those 2 black connections in the middle are needed as well
If no voltage is being supplied to those 2 middle connections, the motor will either not move, or move in a stepping slow motion. If you apply say 12V or higher, it's like it allows the motor to move freely like you would expect. So yeah, it seems those act as some type of relay or switch, but I also noticed as I turned the voltage down going to those two middle connections, it "slowed" down the motor, so I'm also wondering if they act as some type of speed control system...?
I still have a little more experiementing to do as it's been more of a trail and error to this point, but at least I know the motors do work.
I'm just a little concern that the far tip of the motor does get slightly warm when in use, but I'm guessing that's normal?